Film(s) and/or sheet(s) made using polyester compositions containing low amounts of cyclobutanediol

ABSTRACT

Described are film(s) and/or sheet(s) made using polyester compositions comprising polyesters comprising (a) a dicarboxylic acid component comprising 70 to 100 mole % of terephthalic acid residues, and up to 30 mole % of aromatic dicarboxylic acid residues or aliphatic dicarboxylic acid residues; and (b) a glycol component comprising 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues, and 1,4-cyclohexanedimethanol residues.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(e) to U.S.Provisional Application Ser. No. 60/691,567 filed on Jun. 17, 2005, U.S.Provisional Application Ser. No. 60/731,454 filed on Oct. 28, 2005, U.S.Provisional Application Ser. No. 60/731,389, filed on Oct. 28, 2005,U.S. Provisional Application Ser. No. 60/739,058, filed on Nov. 22,2005, U.S. Provisional Application Ser. No. 60/738,869, filed on Nov.22, 2005, U.S. Provisional Application Ser. No. 60/750,692 filed on Dec.15, 2005, U.S. Provisional Application Ser. No. 60/750,693, filed onDec. 15, 2005, U.S. Provisional Application Ser. No. 60/750,682, filedon Dec. 15, 2005, and U.S. Provisional Application Ser. No. 60/750,547,filed on Dec. 15, 2005, all of which are hereby incorporated by thisreference in their entireties.

FIELD OF THE INVENTION

The present invention generally relates to film(s) and/or sheet(s) madefrom polyester compositions made from terephthalic acid, an esterthereof; 2,2,4,4-tetramethyl-1,3-cyclobutanediol or mixtures; and1,4-cyclohexanedimethanol. These compositions useful in the film(s)and/or sheet(s) of the invention having a unique combination of two ormore of high impact strengths, moderate to high glass transitiontemperatures (T_(g)), toughness, certain inherent viscosities, lowductile-to-brittle transition temperatures, good color and clarity, lowdensities, chemical resistance, hydrolytic stability, and longcrystallization half-times, which allow them to be easily formed intofilm and/or sheet.

BACKGROUND OF THE INVENTION

Poly(1,4-cyclohexylenedimethylene terephthalate) (PCT), a polyesterbased solely on terephthalic acid or an ester thereof and1,4-cyclohexanedimethanol, is known in the art and is commerciallyavailable. This polyester crystallizes rapidly upon cooling from themelt, making it very difficult to form amorphous articles by methodsknown in the art such as extrusion, injection molding, and the like. Inorder to slow down the crystallization rate of PCT, copolyesters can beprepared containing additional dicarboxylic acids or glycols such asisophthalic acid or ethylene glycol. These ethylene glycol- orisophthalic acid-modified PCTs are also known in the art and arecommercially available.

One common copolyester used to produce films, sheeting, and moldedarticles is made from terephthalic acid, 1,4-cyclohexanedimethanol, andethylene glycol. While these copolyesters are useful in many end-useapplications, they exhibit deficiencies in properties such as glasstransition temperature and impact strength when sufficient modifyingethylene glycol is included in the formulation to provide for longcrystallization half-times. For example, copolyesters made fromterephthalic acid, 1,4-cyclohexanedimethanol, and ethylene glycol withsufficiently long crystallization half-times can provide amorphousproducts that exhibit what is believed to be undesirably higherductile-to-brittle transition temperatures and lower glass transitiontemperatures than the compositions revealed herein.

The polycarbonate of 4,4′-isopropylidenediphenol (bisphenol Apolycarbonate) has been used as an alternative for polyesters known inthe art and is a well known engineering molding plastic. Bisphenol Apolycarbonate is a clear, high-performance plastic having good physicalproperties such as dimensional stability, high heat resistance, and goodimpact strength. Although bisphenol-A polycarbonate has many goodphysical properties, its relatively high melt viscosity leads to poormelt processability and the polycarbonate exhibits poor chemicalresistance. It is also difficult to thermoform.

Polymers containing 2,2,4,4-tetramethyl-1,3-cyclobutanediol have alsobeen generally described in the art. Generally, however, these polymersexhibit high inherent viscosities and high melt viscosities such thatthe equipment used in industry can be insufficient to manufacture orpost polymerization process these materials.

Thus, there is a need in the art for film(s) and/or sheet(s) comprisinga polyester having two or more properties, chosen from at least one ofthe following: toughness, moderate glass transition temperatures(T_(g)), high impact strength, low ductile-to-brittle transitiontemperatures, chemical resistance, hydrolytic stability, good color andclarity, low densities, and long crystallization half-times and/orthermoformability, which allow them to be easily formed into film(s)and/or sheet(s). In certain embodiments, the polyesters are more easilythermoformed with minimal to no drying required prior to melt processingand/or thermoforming.

SUMMARY OF THE INVENTION

It is believed that certain film(s) and/or sheet(s) comprisingcompositions formed from terephthalic acid, an ester thereof, ormixtures thereof; 1,4-cyclohexanedimethanol; and2,2,4,4-tetramethyl-1,3-cyclobutanediol with certain monomercompositions, inherent viscosities and/or glass transition temperaturesare superior to films and/or sheets made from polyesters known in theart and to polycarbonate with respect to one or more of high impactstrengths, hydrolytic stability, toughness, chemical resistance, goodcolor and clarity, long crystallization half-times, low ductile tobrittle transition temperatures, lower specific gravity, and/orthermoformability. These film(s) and/or sheet(s) are believed to beprocessable on the standard industry equipment.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising at least one polyester which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 10 to 25 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 75 to 90 mole % of 1,4-cyclohexanedimethanol residues,

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;    and

-   wherein the inherent viscosity of the polyester is greater than 0.60    to 1.2 dL/g as determined in 60/40 (wt/wt) phenol/tetrachloroethane    at a concentration of 0.5 g/100 ml at 25° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising at least one polyester which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 10 to 25 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 75 to 90 mole % of 1,4-cyclohexanedimethanol residues,

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;    and

wherein the inherent viscosity of the polyester is greater than 0.60 to0.9 dL/g as determined in 60/40 (wt/wt) phenol/tetrachloroethane at aconcentration of 0.5 g/100 ml at 25° C.

In one aspect, the invention relates to a film or sheet comprising atleast one polyester which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 10 to 25 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 75 to 90 mole % of 1,4-cyclohexanedimethanol residues,

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;    and

-   wherein the inherent viscosity of the polyester is 0.65 to 1.2 dL/g    as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a    concentration of 0.5 g/100 ml at 25° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising at least one polyester which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 11 to 25 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 75 to 89 mole % of 1,4-cyclohexanedimethanol residues,

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;    and

-   wherein the inherent viscosity of the polyester is 0.80 dL/g or less    as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a    concentration of 0.5 g/100 ml at 25° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising at least one polyester which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 12 to 25 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 75 to 88 mole % of 1,4-cyclohexanedimethanol residues,

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;    and

-   wherein the inherent viscosity of the polyester is 0.80 dL/g or less    as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a    concentration of 0.5 g/100 ml at 25° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising at least one polyester which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 13 to 25 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 75 to 87 mole % of 1,4-cyclohexanedimethanol residues,

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;    and

-   wherein the inherent viscosity of the polyester is 0.80 dL/g or less    as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a    concentration of 0.5 g/100 ml at 25° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising at least one polyester which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 14 to 25 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 75 to 86 mole % of 1,4-cyclohexanedimethanol residues,

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;    and

-   wherein the inherent viscosity of the polyester is 0.80 dL/g or less    as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a    concentration of 0.5 g/100 ml at 25° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising at least one polyester which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 14 to 25 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 75 to 86 mole % of 1,4-cyclohexanedimethanol residues,

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;    and

-   wherein the inherent viscosity of the polyester is 0.75 dL/g or less    as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a    concentration of 0.5 g/100 ml at 25° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising at least one polyester which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 14 to 25 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 75 to 86 mole % of 1,4-cyclohexanedimethanol residues,

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;    and

-   wherein the inherent viscosity of the polyester is 0.35 to 0.75 dL/g    as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a    concentration of 0.5 g/100 ml at 25° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising at least one polyester which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 14 to 25 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 75 to 86 mole % of 1,4-cyclohexanedimethanol residues,

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;    and

-   wherein the inherent viscosity of the polyester is 0.50 to 0.75 dL/g    as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a    concentration of 0.5 g/100 ml at 25° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising at least one polyester which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms;

(b) a glycol component comprising:

-   -   i) 14 to 25 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 75 to 86 mole % of 1,4-cyclohexanedimethanol residues, and

(c) residues from at least one branching agent residues;

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;    and-   wherein the inherent viscosity of the polyester is 0.5 to 1.2 dL/g    as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a    concentration of 0.5 g/100 ml at 25° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising at least one polyester which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 17 to 23 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 77 to 83 mole % of 1,4-cyclohexanedimethanol residues,

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;    and

-   wherein the inherent viscosity of the polyester is from 0.60 to less    than 0.72 dL/g as determined in 60/40 (wt/wt)    phenol/tetrachloroethane at a concentration of 0.5 g/100 ml at 25°    C.;

-   wherein the glass transition temperature of the polyester is from 95    to 115° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising at least one polyester which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 14 to 25 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues;    -   ii) 75 to 86 mole % of 1,4-cyclohexanedimethanol residues, and    -   iii) 0.1 to less than 10 mole % of ethylene glycol residues,

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;

-   wherein the inherent viscosity of the polyester is from 0.60 to 0.72    dL/g as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a    concentration of 0.5 g/100 ml at 25° C.; and

-   wherein the glass transition temperature of the polyester is from 95    to 115° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising at least one polyester which comprises:

at least one polyester which comprises:

-   -   (a) a dicarboxylic acid component comprising:        -   i) 70 to 100 mole % of terephthalic acid residues;        -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues            having up to 20 carbon atoms; and        -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues            having up to 16 carbon atoms; and    -   (b) a glycol component comprising:        -   i) 17 to 23 mole % of            2,2,4,4-tetramethyl-1,3-cyclobutanediol residues;        -   ii) 77 to 83 mole % of 1,4-cyclohexanedimethanol residues,            and    -   iii) 0.01 to less than 15 mole % of ethylene glycol residues;

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;

-   wherein the inherent viscosity of the polyester is from 0.35 to 0.75    dL/g as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a    concentration of 0.5 g/100 ml at 25° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising at least one polyester which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 14 to 25 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 75 to 86 mole % of 1,4-cyclohexanedimethanol residues,

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;

-   wherein the inherent viscosity of the polyester is 0.75 dL/g or less    as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a    concentration of 0.5 g/100 ml at 25° C; and

-   wherein the glass transition temperature of the polyester is from 95    to 115° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising:

(I) at least one polyester which comprises:

-   -   (a) a dicarboxylic acid component comprising:        -   i) 70 to 100 mole % of terephthalic acid residues;        -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues            having up to 20 carbon atoms; and        -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues            having up to 16 carbon atoms; and    -   (b) a glycol component comprising:        -   i) 10 to 25 mole % of            2,2,4,4-tetramethyl-1,3-cyclobutanediol residues; and        -   ii) 75 to 90 mole % of 1,4-cyclohexanedimethanol residues;            and

(II) at least one thermal stabilizer and/or reaction products thereof;

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;    and-   wherein the inherent viscosity of the polyester is 0.5 to 1.2 dL/g    as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a    concentration of 0.5 g/100 ml at 25° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising:

(I) at least one polyester which comprises:

-   -   (a) a dicarboxylic acid component comprising:        -   i) 70 to 100 mole % of terephthalic acid residues;        -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues            having up to 20 carbon atoms; and        -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues            having up to 16 carbon atoms; and    -   (b) a glycol component comprising:        -   i) 14 to 25 mole % of            2,2,4,4-tetramethyl-1,3-cyclobutanediol residues; and        -   ii) 75 to 86 mole % of 1,4-cyclohexanedimethanol residues;            and

(II) at least one thermal stabilizer and/or reaction products thereof;

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;    and-   wherein the inherent viscosity of the polyester is 0.5 to 1.2 dL/g    as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a    concentration of 0.5 g/100 ml at 25° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising at least one polyester which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 10 to 25 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 75 to 90 mole % of 1,4-cyclohexanedimethanol residues,

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;

-   wherein the inherent viscosity of the polyester is 0.5 to 1.2 dL/g    as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a    concentration of 0.5 g/100 ml at 25° C.; and

-   wherein the glass transition temperature of the polyester is from 95    to 115° C.

In one aspect, the invention relates to a film or sheet comprising apolyester composition comprising at least one polyester which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 14 to 25 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 75 to 86 mole % of 1,4-cyclohexanedimethanol residues,

-   wherein the total mole % of the dicarboxylic acid component is 100    mole %, and the total mole % of the glycol component is 100 mole %;

-   wherein the inherent viscosity of the polyester is 0.35 to 0.75 dL/g    as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a    concentration of 0.5 g/100 ml at 25° C.; and

-   wherein the glass transition temperature of the polyester is from 95    to 115° C. In one aspect, the film(s) and/or sheet(s) comprising the    polyester compositions useful in the invention contain at least one    polycarbonate.

In one aspect, the polyester compositions useful in the film(s) and/orsheet(s) of the invention contain no polycarbonate.

In one aspect, the polyester useful in the film(s) and/or sheet(s) ofthe invention comprises less than 15 mole % ethylene glycol residues,such as, for example, 0.01 to less than 15 mole % ethylene glycolresidues.

In one aspect, the polyesters useful in the film(s) and/or sheet(s) ofthe invention contain no ethylene glycol residues.

In one aspect, the polyester compositions useful in film(s) and/orsheet(s) of the invention contain at least one thermal stabilizer and/orreaction products thereof.

In one aspect, the polyester useful in the film(s) and/or sheet(s) ofthe invention contains no branching agent or, alternatively, at leastone branching agent is added either prior to or during polymerization ofthe polyester.

In one aspect, the polyesters useful in the film(s) and/or sheet(s) ofthe invention contain at least one branching agent without regard to themethod or sequence in which it is added.

In one aspect, the polyesters useful in the film(s) and/or sheet(s) ofthe invention is made from no 1,3-propanediol, or 1,4-butanediol, eithersingly or in combination. In other aspects, 1,3-propanediol or1,4-butanediol, either singly or in combination, may be used in themaking of the polyesters useful in this invention.

In one aspect of the invention, the mole % ofcis-2,2,4,4-tetramethyl-1,3-cyclobutanediol useful in certain polyestersuseful in the invention is greater than 50 mole % or greater than 55mole % of cis-2,2,4,4-tetramethyl-1,3-cyclobutanediol or greater than 70mole % of cis-2,2,4,4-tetramethyl-1,3-cyclobutanediol; wherein the totalmole percentage of cis-2,2,4,4-tetramethyl-1,3-cyclobutanediol andtrans-2,2,4,4-tetramethyl-1,3-cyclobutanediol is equal to a total of 100mole %.

In one aspect of the invention, the mole % of the isomers of2,2,4,4-tetramethyl-1,3-cyclobutanediol useful in certain polyestersuseful in the invention is from 30 to 70 mole % ofcis-2,2,4,4-tetramethyl-1,3-cyclobutanediol and from 30 to 70 mole % oftrans-2,2,4,4-tetramethyl-1,3-cyclobutanediol; or from 40 to 60 mole %of cis-2,2,4,4-tetramethyl-1,3-cyclobutanediol and from 40 to 60 mole %of trans-2,2,4,4-tetramethyl-1,3-cyclobutanediol, wherein the total molepercentage of cis-2,2,4,4-tetramethyl-1,3-cyclobutanediol andtrans-2,2,4,4-tetramethyl-1,3-cyclobutanediol is equal to a total of 100mole %.

In one aspect, the polyester compositions are useful in film(s) and/orsheet(s) of the invention include but are not limited to extruded and/ormolded articles including but not limited to extruded film(s) and/orsheet(s), calendered film(s) and/or sheet(s), compression molded film(s)and/or sheet(s), solution casted film(s) and/or sheet(s). Methods ofmaking film and/or sheet include but are not limited to extrusion,calendering, compression molding, and solution casting.

Also, in one aspect, use of the polyester compositions minimizes and/oreliminates the drying step prior to melt processing and/orthermoforming.

In one aspect, certain polyesters useful in the film(s) and/or sheet(s)of the invention can be amorphous or semicrystalline. In one aspect,certain polyesters useful in the invention can have a relatively lowcrystallinity. Certain polyesters useful in the invention can thus havea substantially amorphous morphology, meaning that the polyesterscomprise substantially unordered regions of polymer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the effect of comonomer on the fastestcrystallization half-times of modified PCT copolyesters.

FIG. 2 is a graph showing the effect of comonomer on thebrittle-to-ductile transition temperature (T_(bd)) in a notched impactstrength Izod test (ASTM D256, ⅛-in thick, 10-mil notch).

FIG. 3 is a graph showing the effect of2,2,4,4-tetramethyl-1,3-cyclobutanediol composition on the glasstransition temperature (Tg) of the copolyester.

DETAILED DESCRIPTION OF THE INVENTION

The present invention may be understood more readily by reference to thefollowing detailed description of certain embodiments of the inventionand the working examples.

As used herein, the term “polyester” includes copolyesters. Inaccordance with the purpose(s) of this invention, certain embodiments ofthe invention are described in the Summary of the Invention and arefurther described herein below. Also, other embodiments of the inventionare described herein.

It is believed that polyesters useful in the film(s) and/or sheet(s)having the compositions described herein can have a combination of twoor more physical properties such as high impact strengths, moderate tohigh glass transition temperatures, chemical resistance, hydrolyticstability, low ductile-to-brittle transition temperatures, good colorand clarity, low densities, and long crystallization half-times, andgood processability thereby easily permitting them to be formed intofilm and/or sheet. In addition, the film or sheet article described incertain embodiments of the invention can be readily thermoformed withoutthe need to pre-dry the film or sheet. In some of the embodiments of theinvention, the advantageously superior combination of the properties ofgood impact strength, heat resistance, chemical resistance, density,processability, and/or the combination of at least two of all four ofthe described properties have never before been believed to be presentin a polyester containing the composition(s) as disclosed herein.

The term “polyester”, as used herein, is intended to include“copolyesters” and is understood to mean a synthetic polymer prepared bythe reaction of one or more difunctional carboxylic acids and/ormultifunctional carboxylic acids with one or more difunctional hydroxylcompounds and/or multifunctional hydroxyl compounds. Typically thedifunctional carboxylic acid can be a dicarboxylic acid and thedifunctional hydroxyl compound can be a dihydric alcohol such as, forexample, glycols and diols. The term “glycol” as used herein includes,but is not limited to, diols, glycols, and/or multifunctional hydroxylcompounds, for example, branching agents. Alternatively, thedifunctional carboxylic acid may be a hydroxy carboxylic acid such as,for example, p-hydroxybenzoic acid, and the difunctional hydroxylcompound may be an aromatic nucleus bearing 2 hydroxyl substituents suchas, for example, hydroquinone. The term “residue”, as used herein, meansany organic structure incorporated into a polymer through apolycondensation and/or an esterification reaction from thecorresponding monomer. The term “repeating unit”, as used herein, meansan organic structure having a dicarboxylic acid residue and a diolresidue bonded through a carbonyloxy group. Thus, for example, thedicarboxylic acid residues may be derived from a dicarboxylic acidmonomer or its associated acid halides, esters, salts, anhydrides, ormixtures thereof. As used herein, therefore, the term dicarboxylic acidis intended to include dicarboxylic acids and any derivative of adicarboxylic acid, including its associated acid halides, esters,half-esters, salts, half-salts, anhydrides, mixed anhydrides, ormixtures thereof, useful in a reaction process with a diol to makepolyester. Furthermore, as used herein, the term “diacid” includes butis not limited to multifunctional acids, for example, branching agents.As used herein, the term “terephthalic acid” is intended to includeterephthalic acid itself and residues thereof as well as any derivativeof terephthalic acid, including its associated acid halides, esters,half-esters, salts, half-salts, anhydrides, mixed anhydrides, ormixtures thereof or residues thereof useful in a reaction process with adiol to make polyester.

In one embodiment, terephthalic acid may be used as the startingmaterial. In another embodiment, dimethyl terephthalate may be used asthe starting material. In another embodiment, mixtures of terephthalicacid and dimethyl terephthalate may be used as the starting materialand/or as an intermediate material.

The polyesters used in the present invention typically can be preparedfrom dicarboxylic acids and diols which react in substantially equalproportions and are incorporated into the polyester polymer as theircorresponding residues. The polyesters of the present invention,therefore, can contain substantially equal molar proportions of acidresidues (100 mole %) and diol (and/or multifunctional hydroxylcompound) residues (100 mole %) such that the total moles of repeatingunits is equal to 100 mole %. The mole percentages provided in thepresent disclosure, therefore, may be based on the total moles of acidresidues, the total moles of diol residues, or the total moles ofrepeating units. For example, a polyester containing 30 mole %isophthalic acid, based on the total acid residues, means the polyestercontains 30 mole % isophthalic acid residues out of a total of 100 mole% acid residues. Thus, there are 30 moles of isophthalic acid residuesamong every 100 moles of acid residues. In another example, a polyestercontaining 25 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol, based onthe total diol residues, means the polyester contains 25 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues out of a total of 100mole % diol residues. Thus, there are 25 moles of2,2,4,4-tetramethyl-1,3-cyclobutanediol residues among every 100 molesof diol residues.

In other aspects of the invention, the Tg of the polyesters useful inthe film(s) and/or sheet(s) of the invention can be at least one of thefollowing ranges: 80 to 125° C.; 80 to 120° C.; 80 to 115° C.; 80 to110° C.; 80 to 105° C.; 80 to 100° C.; 80 to 95° C.; 80 to 90° C.; 80 to85° C.; 85 to 125° C.; 85 to 120° C.; 85 to 115° C.; 85 to 110° C.; 85to 105° C.; 85 to 100° C.; 85 to 95° C.; 85 to 90° C.; 90 to 125° C.; 90to 120° C.; 90 to 115° C.; 90 to 110° C.; 90 to 105° C.; 90 to 100° C.;90 to 95° C.; 95 to 125° C.; 95 to 120° C.; 95 to 115° C.; 95 to 110°C.; 95 to 105° C.; 95 to less than 105° C.; 95 to 100° C.; 100 to 125°C.; 100 to 120° C.; 100 to 115° C.; 100 to 110° C.; 105 to 125° C.; 105to 120° C.; 105 to 115° C.; 105 to 110° C.; greater than 105 to 125° C.;greater than 105 to 120° C.; greater than 105 to 115° C.; greater than105 to 110° C.; 110 to 125° C.; 110 to 120° C.; 110 to 115° C.; greaterthan 110 to 125° C.; greater than 110 to 120° C.; greater than 110 to115° C.; 115 to 125° C.; and 115 to 120° C.

In other aspects of the invention, the glycol component for thepolyesters useful in the film(s) and/or sheet(s) of the inventioninclude but are not limited to at least one of the followingcombinations of ranges: 10 to 25 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 75 to 90 mole %1,4-cyclohexanedimethanol; 10 to 24 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 76 to 90 mole %1,4-cyclohexanedimethanol 10 to 20 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 80 to 90 mole %1,4-cyclohexanedimethanol; 10 to less than 20 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and greater than 80 to 90 mole %1,4-cyclohexanedimethanol; 10 to 19 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 81 to 90 mole %1,4-cyclohexanedimethanol; 10 to 18 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 82 to 90 mole %1,4-cyclohexanedimethanol; and 10 to 15 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 85 to 90 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for the film(s)and/or sheet(s) useful in the polyesters useful in the invention includebut are not limited to at least one of the following combinations ofranges: greater than 10 to 25 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 75 to less than 90 mole %1,4-cyclohexanedimethanol; greater than 10 to 24 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 76 to less than 90 mole %1,4-cyclohexanedimethanol greater than 10 to 20 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 80 to less than 90 mole %1,4-cyclohexanedimethanol; greater than 10 to less than 20 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and greater than 80 to less than90 mole % 1,4-cyclohexanedimethanol; greater than 10 to 19 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 81 to less than 90 mole %1,4-cyclohexanedimethanol; greater than 10 to 18 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 82 to less than 90 mole %1,4-cyclohexanedimethanol; and greater than 10 to 15 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 85 to less than 90 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the film(s) and/or sheet(s) useful in the inventioninclude but are not limited to at least one of the followingcombinations of ranges: 11 to 25 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 75 to 89 mole %1,4-cyclohexanedimethanol; 11 to 24 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 76 to 89 mole %1,4-cyclohexanedimethanol; 11 to 20 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 80 to 89 mole %1,4-cyclohexanedimethanol; 11 to 19 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 81 to 89 mole %1,4-cyclohexnedimethanol; 11 to 18 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 82 to 89 mole %1,4-cyclohexanedimethanol; and 11 to 15 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 85 to 89 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the film(s) and/or sheet(s) useful in the inventioninclude but are not limited to at least one of the followingcombinations of ranges: 12 to 25 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 75 to 88 mole %1,4-cyclohexanedimethanol; 12 to 24 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 76 to 88 mole %1,4-cyclohexanedimethanol; 12 to 20 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 80 to 88 mole %1,4-cyclohexanedimethanol; 12 to 19 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 81 to 88 mole %1,4-cyclohexanedimethanol; 12 to 18 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 82 to 88 mole %1,4-cyclohexanedimethanol; 12 to 18 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 82 to 88 mole %1,4-cyclohexanedimethanol; and 12 to 15 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 85 to 88 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the film(s) and/or sheet(s) useful in the inventioninclude but are not limited to at least one of the followingcombinations of ranges: 13 to 25 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 75 to 87 mole %1,4-cyclohexanedimethanol; 13 to 24 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 76 to 87 mole %1,4-cyclohexanedimethanol; 13 to 20 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 80 to 87 mole %1,4-cyclohexanedimethanol; 13 to 19 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 81 to 87 mole %1,4-cyclohexanedimethanol; 13 to 18 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 82 to 87 mole %1,4-cyclohexanedimethanol; and 13 to 15 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 85 to 87 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the film(s) and/or sheet(s) useful in the inventioninclude but are not limited to at least one of the followingcombinations of ranges: 14 to 25 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 75 to 86 mole %1,4-cyclohexanedimethanol; 14 to 24 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 76 to 86 mole %1,4-cyclohexanedimethanol; 14 to 20 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 80 to 86 mole %1,4-cyclohexanedimethanol; 14 to 19 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 81 to 86 mole %1,4-cyclohexanedimethanol; 14 to 18 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 82 to 86 mole %1,4-cyclohexanedimethanol; 15 to 25 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 75 to 85 mole %1,4-cyclohexanedimethanol; 15 to 24 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 76 to 85 mole %1,4-cyclohexanedimethanol; 15 to 20 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 80 to 85 mole %1,4-cyclohexanedimethanol ;16 to 24 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 76 to 84 mole %1,4-cyclohexanedimethanol; 16 to 23 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 77 to 84 mole %1,4-cyclohexanedimethanol; 17 to 24 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 76 to 83 mole %1,4-cyclohexanedimethanol; 17 to 23 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 77 to 83 mole %1,4-cyclohexanedimethanol; and 20 to 25 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 75 to 80 mole %1,4-cyclohexanedimethanol.

In addition to the diols set forth above, the polyesters useful in thepolyester compositions of the film(s) and/or sheet(s) useful in theinvention may also be made from 1,3-propanediol, 1,4-butanediol, ormixtures thereof. It is contemplated that compositions of the inventionmade from 1,3-propanediol, 1,4-butanediol, or mixtures thereof canpossess at least one of the Tg ranges described herein, at least one ofthe inherent viscosity ranges described herein, and/or at least one ofthe glycol or diacid ranges described herein. In addition or in thealternative, the polyesters made from 1,3-propanediol or 1,4-butanediolor mixtures thereof may also be made from 1,4-cyclohexanedmethanol in atleast one of the following amounts: from 0.1 to 80 mole %; from 0.1 to99 mole %; from 0.1 to 90 mole %; from 0.1 to 80 mole %; 0.1 to 70 mole%; from 0.1 to 60 mole %; from 0.1 to 50 mole %; from 0.1 to 40 mole %;from 0.1 to 35 mole %; from 0.1 to 30 mole %; from 0.1 to 25 mole %;from 0.1 to 20 mole %; from 0.1 to 15 mole %; from 0.1 to 10 mole %;from 0.1 to 5 mole %; from 1 to 99 mole %; from 1 to 90 mole %; from 1to 80 mole %; from 1 to 70 mole %; from 1 to 60 mole %; from 1 to 50mole %; from 1 to 40 mole %; from 1 to 35 mole %; from 1 to 30 mole %;from 1 to 25 mole %; from 1 to 20 mole %; from 1 to 15 mole %; from 1 to10 mole %; from 1 to 5 mole %; from 5 to 99 mole %; from 5 to 90 mole %;5 to 80 mole %; 5 to 70 mole %; from 5 to 60 mole %; from 5 to 50 mole%; from 5 to 40 mole %; from 5 to 35 mole %; from 5 to 30 mole %; from 5to 25 mole %; from 5 to 20 mole %; and from 5 to 15 mole %; from 5 to 10mole %; from 10 to 99 mole %; from 10 to 90 mole %; from 10 to 80 mole%; from 10 to 70 mole %; from 10 to 60 mole %; from 10 to 50 mole %;from 10 to 40 mole %; from 10 to 35 mole %; from 10 to 30 mole %; from10 to 25 mole %; from 10 to 20 mole %; from 10 to 15 mole %; from 20 to99 mole %; from 20 to 90 mole %; from 20 to 80 mole %; from 20 to 70mole %; from 20 to 60 mole %; from 20 to 50 mole %; from 20 to 40 mole%; from 20 to 35 mole %; from 20 to 30 mole %; and from 20 to 25 mole %.

For certain embodiments of the invention, the polyesters useful in thefilm(s) and/or sheet(s) useful in the invention may exhibit at least oneof the following inherent viscosities as determined in 60/40 (wt/wt)phenol/tetrachloroethane at a concentration of 0.5 g/100 ml at 25° C.:0.1 to 0.80 dL/g; 0.1 to less than 0.80 dL/g; 0.10 to 0.75 dL/g; 0.10 toless than 0.75 dL/g; 0.10 to 0.72 dL/g; 0.10 to 0.70 dL/g; 0.10 to lessthan 0.70 dL/g; 0.10 to 0.68 dL/g; 0.10 to less than 0.68 dL/g; 0.10 to0.65 dL/g; 0.20 to 0.80 dL/g; 0.2 to less than 0.80 dL/g; 0.20 to 0.75dL/g; 0.20 to less than 0.75 dL/g; 0.20 to 0.72 dL/g; 0.20 to 0.70 dL/g;0.20 to less than 0.70 dL/g; 0.20 to 0.68 dL/g; 0.20 to less than 0.68dL/g; 0.20 to 0.65 dL/g; 0.35 to 0.80 dL/g; 0.35 to less than 0.80 dL/g;0.35 to 0.80 dL/g; 0.35 to 0.75 dL/g; 0.35 to less than 0.75 dL/g; 0.35to 0.72 dL/g; 0.35 to 0.70 dL/g; 0.35 to less than 0.70 dL/g; 0.35 to0.68 dL/g; 0.35 to less than 0.68 dL/g; 0.35 to 0.65 dL/g; 0.40 to 0.80dL/g; 0.40 to less than 0.80 dL/g 0.40 to 0.75 dL/g; 0.40 to less than0.75 dL/g; 0.40 to 0.72 dL/g; 0.40 to 0.70 dL/g; 0.40 to less than 0.70dL/g; 0.40 to 0.68 dL/g; 0.40 to less than 0.68 dL/g; 0.40 to 0.65 dL/g;0.42 to 0.80 dL/g; 0.42 to less than 0.80 dL/g; greater than 0.42 to0.80 dL/g; greater than 0.42 to less than 0.80 dL/g greater than 0.42 to0.75 dL/g; greater than 0.42 to less than 0.75 dL/g; greater than 0.42to 0.72 dL/g; greater than 0.42 to less than 0.70 dL/g; greater than0.42 to 0.68 dL/g; greater than 0.42 to less than 0.68 dL/g; and greaterthan 0.42 to 0.65 dL/g.

For certain embodiments of the invention, the polyesters useful in thefilm(s) and/or sheet(s) useful in the invention may exhibit at least oneof the following inherent viscosities as determined in 60/40 (wt/wt)phenol/tetrachloroethane at a concentration of 0.5 g/100 ml at 25° C.:0.45 to 0.80 dL/g; 0.45 to less than 0.80 dL/g; 0.45 to 0.75 dL/g; 0.45to less than 0.75 dL/g; 0.45 to 0.72 dL/g; 0.45 to 0.70 dL/g; 0.45 toless than 0.70 dL/g; 0.45 to 0.68 dL/g; 0.45 to less than 0.68 dL/g;0.45 to 0.65 dL/g; 0.50 to 0.80 dL/g; 0.50 to less than 0.80 dL/g; 0.50to 0.75 dL/g; 0.50 to less than 0.75 dL/g; 0.50 to 0.72 dL/g; 0.50 to0.70 dL/g; 0.50 to less than 0.70 dL/g; 0.50 to 0.68 dL/g; 0.50 to lessthan 0.68 dL/g; 0.50 to 0.65 dL/g; 0.55 to 0.80 dL/g; 0.55 to less than0.80 dL/g; 0.55 to 0.75 dL/g; 0.55 to less than 0.75 dL/g; 0.55 to 0.72dL/g; 0.55 to 0.70 dL/g; 0.55 to less than 0.70 dL/g; 0.55 to 0.68 dL/g;0.55 to less than 0.68 dL/g; 0.55 to 0.65 dL/g; 0.58 to 0.80 dL/g; 0.58to less than 0.80 dL/g; 0.58 to 0.75 dL/g; 0.58 to less than 0.75 dL/g;0.58 to 0.72 dL/g; 0.58 to 0.70 dL/g; 0.58 to less than 0.70 dL/g; 0.58to 0.68 dL/g; 0.58 to less than 0.68 dL/g; 0.58 to 0.65 dL/g; 0.60 to0.80 dL/g; 0.60 to less than 0.80 dL/g; 0.60 to 0.75 dL/g; 0.60 to lessthan 0.75 dL/g; 0.60 to 0.72 dL/g; 0.60 to 0.70 dL/g; 0.60 to less than0.70 dL/g; 0.60 to 0.68 dL/g; 0.60 to less than 0.68 dL/g; 0.60 to 0.65dL/g; greater than 0.60 to less than 0.80 dL/g; greater than 0.60 to0.75 dL/g; greater than 0.60 to less than 0.75 dL/g; greater than 0.60to 0.72 dL/g; 0.65 to 0.80 dL/g; 0.65 to less than 0.80 dL/g; 0.65 to0.75 dL/g; 0.65 to less than 0.75 dL/g; 0.65 to 0.72 dL/g; 0.65 to 0.70dL/g; 0.65 to less than 0.70 dL/g; 0.68 to 0.80 dL/g; 0.68 to 0.75 dL/g;0.68 to less than 0.75 dL/g; 0.68 to 0.72 dL/g; 0.70 to 0.80 dL/g; 0.70to less than 0.80 dL/g; 0.70 to 0.75 dL/g; and 0.70 to less than 0.75dL/g.

For certain embodiments of the invention, the polyesters useful in thefilm(s) and/or sheet(s) useful in the invention may exhibit at least oneof the following inherent viscosities as determined in 60/40 (wt/wt)phenol/tetrachloroethane at a concentration of 0.5 g/100 ml at 25° C.:0.40 to 1.2 dL/g; 0.40 to 1.1 dL/g; 0.40 to 1 dL/g; 0.40 to less than 1dL/g; 0.40 to 0.98 dL/g; 0.40 to 0.95 dL/g; 0.40 to 0.90 dL/g; 0.40 to0.85 dL/g; 0.45 to 1.2 dL/g; 0.45 to 1.1 dL/g; 0.45 to 1 dL/g; 0.45 toless than 1 dL/g; 0.45 to 0.98 dL/g; 0.45 to 0.95 dL/g; 0.45 to 0.90dL/g; 0.45 to 0.85 dL/g; 0.50 to 1.2 dL/g; 0.50 to 1.1 dL/g; 0.50 to 1dL/g; 0.50 to less than 1 dL/g; 0.50 to 0.98 dL/g; 0.50 to 0.95 dL/g;0.50 to 0.90 dL/g; 0.50 to 0.85 dL/g; 0.55 to 1.2 dL/g; 0.55 to 1.1dL/g; 0.55 to 1 dL/g; 0.55 to less than 1 dL/g; 0.55 to 0.98 dL/g; 0.55to 0.95 dL/g; 0.55 to 0.90 dL/g; 0.55 to 0.85 dL/g; 0.58 to 1.2 dL/g;0.58 to 1.1 dL/g; 0.58 to 1 dL/g; 0.58 to less than 1 dL/g; 0.58 to 0.98dL/g; 0.58 to 0.95 dL/g; 0.58 to 0.90 dL/g; 0.58 to 0.85 dL/g; 0.60 to1.2 dL/g; 0.60 to 1.1 dL/g; 0.60 to 1 dL/g; 0.60 to less than 1 dL/g;0.60 to 0.98 dL/g; 0.60 to 0.95 dL/g; 0.60 to 0.90 dL/g; 0.60 to 0.85dL/g; 0.65 to 1.2 dL/g; 0.65 to 1.1 dL/g; 0.65 to 1 dL/g; 0.65 to lessthan 1 dL/g; 0.65 to 0.98 dL/g; 0.65 to 0.95 dL/g; 0.65 to 0.90 dL/g;0.65 to 0.85 dL/g; 0.68 to 1.2 dL/g; 0.68 to 1.1 dL/g; 0.68 to 1 dL/g;0.68 to less than 1 dL/g; 0.68 to 0.98 dL/g; 0.68 to 0.95 dL/g; 0.68 to0.90 dL/g; 0.68 to 0.85 dL/g; 0.70 to 1.2 dL/g; 0.70 to 1.1 dL/g; 0.70to 1 dL/g; 0.70 to less than 1 dL/g; 0.70 to 0.98 dL/g; 0.70 to 0.95dL/g; 0.70 to 0.90 dL/g; 0.70 to 0.85 dL/g; 0.75 to 1.2 dL/g; 0.75 to1.1 dL/g; 0.75 to 1 dL/g; 0.75 to less than 1 dL/g; 0.75 to 0.98 dL/g;0.75 to 0.95 dL/g; 0.75 to 0.90 dL/g; 0.75 to 0.85 dL/g; greater than0.76 dL/g to 1.2 dL/g; greater than 0.76 dL/g to 1.1 dL/g; greater than0.76 dL/g to 1 dL/g; greater than 0.76 dL/g to less than 1 dL/g; greaterthan 0.76 dL/g to 0.98 dL/g; greater than 0.76 dL/g to 0.95 dL/g;greater than 0.76 dL/g to 0.90 dL/g; greater than 0.80 dL/g to 1.2 dL/g;greater than 0.80 dL/g to 1.1 dL/g; greater than 0.80 dL/g to 1 dL/g;greater than 0.80 dL/g to less than 1 dL/g; greater than 0.80 dL/g to1.2 dL/g; greater than 0.80 dL/g to 0.98 dL/g; greater than 0.80 dL/g to0.95 dL/g; greater than 0.80 dL/g to 0.90 dL/g.

It is contemplated that the polyester compositions of the film(s) and/orsheet(s) useful in the invention can possess at least one of theinherent viscosity ranges described herein and at least one of themonomer ranges for the compositions described herein unless otherwisestated. It is also contemplated that the polyester compositions of thefilm(s) and/or sheet(s) useful in the invention can possess at least oneof the Tg ranges described herein and at least one of the monomer rangesfor the compositions described herein unless otherwise stated. It isalso contemplated that the polyester compositions of the invention canpossess at least one of the Tg ranges described herein, at least one ofthe inherent viscosity ranges described herein, and at least one of themonomer ranges for the compositions described herein unless otherwisestated.

For the desired polyester useful in the film(s) and/or sheet(s) of theinvention, the molar ratio of cis/trans2,2,4,4-tetramethyl-1,3-cyclobutanediol can vary from the pure form ofeach or mixtures thereof. In certain embodiments, the molar percentagesfor cis and/or trans 2,2,4,4-tetramethyl-1,3-cyclobutanediol are greaterthan 50 mole % cis and less than 50 mole % trans; or greater than 55mole % cis and less than 45 mole % trans; or 30 to 70 mole % cis and 70to 30 % mole % trans; or 40 to 60 mole % cis and 60 to 40 mole % trans;or 50 to 70 mole % trans and 50 to 30 mole % cis or 50 to 70 mole % cisand 50 to 30 mole % trans; or 60 to 70 mole % cis and 30 to 40 mole %trans; or greater than 70 mole cis and less than 30 mole % trans;wherein the total sum of the mole percentages for cis- and trans-2,2,4,4-tetramethyl-1,3-cyclobutanediol is equal to 100 mole %. Themolar ratio of cis/trans 1,4-cyclohexandimethanol can vary within therange of 50/50 to 0/100, for example, such as between 40/60 to 20/80.

In certain embodiments, terephthalic acid, an ester thereof, such as,for example, dimethyl terephthalate, or a mixture of terephthalic acidand an ester thereof, makes up most or all of the dicarboxylic acidcomponent used to form the polyesters useful in the film(s) and/orsheet(s) useful in the invention. In certain embodiments, terephthalicacid residues can make up a portion or all of the dicarboxylic acidcomponent used to form the present polyester at a concentration of atleast 70 mole %, such as at least 80 mole %, at least 90 mole %, atleast 95 mole %, at least 99 mole %, or a mole % of 100. In certainembodiments, higher amounts of terephthalic acid can be used in order toproduce a higher impact strength polyester. For the purposes of thisdisclosure, the terms “terephthalic acid” and dimethyl terephthalate”are used interchangeably herein. In one embodiment, dimethylterephthalate is part or all of the dicarboxylic acid component used tomake the polyesters useful in the present invention. In all embodiments,ranges of from 70 to 100 mole %; or 80 to 100 mole %; or 90 to 100 mole%; or 99 to 100 mole %; or 100 mole % terephthalic acid and/or dimethylterephthalate and/or mixtures thereof may be used.

In addition to terephthalic acid residues, the dicarboxylic acidcomponent of the polyesters useful in the film(s) and/or sheet(s) usefulin the invention can comprise up to 30 mole %, up to 20 mole %, up to 10mole %, up to 5 mole %, or up to 1 mole % modifying aromaticdicarboxylic acids. Yet another embodiment contains 0 mole % modifyingaromatic dicarboxylic acids. Thus, if present, it is contemplated thatthe amount of one or more modifying aromatic dicarboxylic acids canrange from any of these preceding endpoint values including, forexample, from 0.01 to 30 mole %, 0.01 to 20 mole %, from 0.01 to 10 mole%, from 0.01 to 5 mole % and from 0.01 to 1 mole. In one embodiment,modifying aromatic dicarboxylic acids that may be used in the presentinvention include but are not limited to those having up to 20 carbonatoms, and which can be linear, para-oriented, or symmetrical. Examplesof modifying aromatic dicarboxylic acids which may be used in thisinvention include, but are not limited to, isophthalic acid,4,4′-biphenyidicarboxylic acid, 1,4-, 1,5-, 2,6-,2,7-naphthalenedicarboxylic acid, and trans-4,4′-stilbenedicarboxylicacid, and esters thereof. In one embodiment, the modifying aromaticdicarboxylic acid is isophthalic acid.

The carboxylic acid component of the polyesters useful in the film(s)and/or sheet(s) useful in the invention can be further modified with upto 10 mole %, up to 5 mole % or up to 1 mole % of one or more aliphaticdicarboxylic acids containing 2-16 carbon atoms, such as, for example,malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic anddodecanedioic dicarboxylic acids. Certain embodiments can also comprise0.01 or more mole %, 0.1 or more mole %, 1 or more mole %, 5 or moremole %, or 10 or more mole % of one or more modifying aliphaticdicarboxylic acids. Yet another embodiment contains 0 mole % modifyingaliphatic dicarboxylic acids. Thus, if present, it is contemplated. thatthe amount of one or more modifying aliphatic dicarboxylic acids canrange from any of these preceding endpoint values including, forexample, from 0.01 to 10 mole % and from 0.1 to 10 mole %. The totalmole % of the dicarboxylic acid component is 100 mole %.

Esters of terephthalic acid and the other modifying dicarboxylic acidsor their corresponding esters and/or salts may be used instead of thedicarboxylic acids. Suitable examples of dicarboxylic acid estersinclude, but are not limited to, the dimethyl, diethyl, dipropyl,diisopropyl, dibutyl, and diphenyl esters. In one embodiment, the estersare chosen from at least one of the following: methyl, ethyl, propyl,isopropyl, and phenyl esters.

The 1,4-cyclohexanedimethanol may be cis, trans, or a mixture thereof,such as a cis/trans ratio of 60:40 to 40:60. In another embodiment, thetrans-1,4-cyclohexanedimethanol can be present in an amount of 60 to 80mole

The glycol component of the polyester portion of the polyestercomposition useful in the invention can contain 25 mole % or less of oneor more modifying glycols which are not2,2,4,4-tetramethyl-1,3-cyclobutanediol or 1,4-cyclohexanedimethanol; inone embodiment, the polyester useful in the film(s) and/or sheet(s)useful in the invention may contain less than 15 mole % or of one ormore modifying glycols. In another embodiment, the polyesters useful inthe invention can contain 10 mole % or less of one or more modifyingglycols. In another embodiment, the polyesters useful in the film(s)and/or sheet(s) useful in the invention can contain 5 mole % or less ofone or more modifying glycols. In another embodiment, the polyestersuseful in the film(s) and/or sheet(s) useful in the invention cancontain 3 mole % or less of one or more modifying glycols. In anotherembodiment, the polyesters useful in the film(s) and/or sheet(s) usefulin the invention can contain 0 mole % modifying glycols. Thus, ifpresent, it is contemplated that the amount of one or more modifyingglycols can range from any of these preceding endpoint values including,for example, from 0.01 to 15 mole % and from 0.1 to 10 mole %.

Modifying glycols useful in polyesters of the film(s) and/or sheet(s)useful in the invention refer to diols other than2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1,4-cyclohexanedimethanoland can contain 2 to 16 carbon atoms. Examples of suitable modifyingglycols include, but are not limited to, ethylene glycol, diethyleneglycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol,1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, p-xylene glycol, ormixtures thereof. One embodiment for the modifying glycol is ethyleneglycol. Other modifying glycols include, but are not limited to,1,3-propanediol and 1,4-butanediol. In another embodiment, ethyleneglycol is excluded as a modifying diol. In another embodiment,1,3-propanediol and 1,4-butanediol are excluded as modifying diols. Inanother embodiment, 2,2-dimethyl-1,3-propanediol is excluded as amodifying diol.

The polyesters and/or the polycarbonates useful in the polyesterscompositions of the film(s) and/or sheet(s) useful in the invention cancomprise from 0 to 10 mole percent, for example, from 0.01 to 5 molepercent, from 0.01 to 1 mole percent, from 0.05 to 5 mole percent, from0.05 to 1 mole percent, or from 0.1 to 0.7 mole percent, or 0.1 to 0.5mole percent, based the total mole percentages of either the diol ordiacid residues; respectively, of one or more residues of a branchingmonomer, also referred to herein as a branching agent, having 3 or morecarboxyl substituents, hydroxyl substituents, or a combination thereof.In certain embodiments, the branching monomer or agent may be addedprior to and/or during and/or after the polymerization of the polyester.The polyester(s) useful in the film(s) and/or sheet(s) useful in theinvention can thus be linear or branched. The polycarbonate can also belinear or branched. In certain embodiments, the branching monomer oragent may be added prior to and/or during and/or after thepolymerization of the polycarbonate.

Examples of branching monomers include, but are not limited to,multifunctional acids or multifunctional alcohols such as trimelliticacid, trimellitic anhydride, pyromellitic dianhydride,trimethylolpropane, glycerol, pentaerythritol, citric acid, tartaricacid, 3-hydroxyglutaric acid and the like. In one embodiment, thebranching monomer residues can comprise 0.1 to 0.7 mole percent of oneor more residues chosen from at least one of the following: trimelliticanhydride, pyromellitic dianhydride, glycerol, sorbitol,1,2,6-hexanetriol, pentaerythritol, trimethylolethane, and/or trimesicacid. The branching monomer may be added to the polyester reactionmixture or blended with the polyester in the form of a concentrate asdescribed, for example, in U.S. Pat. Nos. 5,654,347 and 5,696,176, whosedisclosure regarding branching monomers is incorporated herein byreference.

The glass transition temperature (Tg) of the polyesters useful in the ifilm(s) and/or sheet(s) useful in the invention was determined using aTA DSC 2920 from Thermal Analyst Instrument at a scan rate of 20°C./min.

Because of the long crystallization half-times (e.g., greater than 5minutes) at 170° C. exhibited by certain polyesters useful in thefilm(s) and/or sheet(s) useful in the present invention, it can bepossible to produce articles including, but not limited to, injectionmolded parts, injection blow molded articles, injection stretch blowmolded articles, extruded film, extruded sheet, extrusion blow moldedarticles, extrusion stretch blow molded articles, and fibers. Athermoformable sheet is an example of an article of manufacture providedby this invention. The polyesters useful in the film(s) and/or sheet(s)useful in the invention can be amorphous or semicrystalline. In oneaspect, certain polyesters useful in the film(s) and/or sheet(s) usefulin the invention can have a relatively low crystallinity. Certainpolyesters useful in the film(s) and/or sheet(s) useful in the inventioncan thus have a substantially amorphous morphology, meaning that thepolyesters comprise substantially unordered regions of polymer.

In one embodiment; an “amorphous” polyester can have a crystallizationhalf-time of greater than 5 minutes at 170° C.; or greater than 10minutes at 170° C.; or greater than 50 minutes at 170° C.; or greaterthan 100 minutes at 170° C. In one embodiment, of the invention, thecrystallization half-times of the polyesters useful in the film(s)and/or sheet(s) useful in the invention can be greater than 1,000minutes at 170° C. In another embodiment of the invention, thecrystallization half-times of the polyesters useful in the film(s)and/or sheet(s) useful in the invention can be greater than 10,000minutes at 170° C. The crystallization half time of the polyester, asused herein, may be measured using methods well-known to persons ofskill in the art. For example, the crystallization half time of thepolyester, t_(1/2), can be determined by measuring the lighttransmission of a sample via a laser and photo detector as a function oftime on a temperature controlled hot stage. This measurement can be doneby exposing the polymers to a temperature, T_(max), and then cooling itto the desired temperature. The sample can then be held at the desiredtemperature by a hot stage while transmission measurements are made as afunction of time. Initially, the sample can be visually clear with highlight transmission, and becomes opaque as the sample crystallizes. Thecrystallization half-time is the time at which the light transmission ishalfway between the initial transmission and the final transmission.T_(max) is defined as the temperature required to melt the crystallinedomains of the sample (if crystalline domains are present). The samplecan be heated to Tmax to condition the sample prior to crystallizationhalf time measurement. The absolute Tmax temperature is different foreach composition. For example PCT can be heated to some temperaturegreater than 290° C. to melt the crystalline domains.

As shown in Table 1 and FIG. 1 of the Examples,2,2,4,4-tetramethyl-1,3-cyclobutanediol is more effective than othercomonomers such ethylene glycol and isophthalic acid at increasing thecrystallization half-time, i.e., the time required for a polymer toreach half of its maximum crystallinity. By decreasing thecrystallization rate of PCT, i.e. increasing the crystallizationhalf-time, amorphous articles based on modified PCT may be fabricated bymethods known in the art such as extrusion, injection molding, and thelike. As shown in Table 1, these materials can exhibit higher glasstransition temperatures and lower densities than other modified PCTcopolyesters.

The polyesters can exhibit an improvement in toughness combined withprocessability for some of the embodiments of the invention. Forexample, lowering the inherent viscosity slightly of the polyestersuseful in the film(s) and/or sheet(s) useful in the invention results ina more processable. melt viscosity while retaining good physicalproperties of the polyesters such as toughness and heat resistance.

Increasing the content of 1,4-cyclohexanedimethanol in a copolyesterbased on terephthalic acid, ethylene glycol, and1,4-cyclohexanedimethanol can improve toughness, which can be determinedby the brittle-to-ductile transition temperature in a notched Izodimpact strength test as measured by ASTM D256. This toughnessimprovement, by lowering of the brittle-to-ductile transitiontemperature with 1,4-cyclohexanedimethanol, is believed to occur due tothe flexibility and conformational behavior of 1,4-cyclohexanedimethanolin the copolyester. Incorporating2,2,4,4-tetramethyl-1,3-cyclobutanediol into PCT is believed to improvetoughness, by lowering the brittle-to-ductile transition temperature, asshown in Table 2 and FIG. 2 of the Examples.

In one embodiment, the melt viscosity of the polyester(s) useful in thefilm(s) and/or sheet(s) useful in the invention is less than 30,000poise as measured a 1 radian/second on a rotary melt rheometer at 290°C. In another embodiment, the melt viscosity of the polyester(s) usefulin the film(s) and/or sheet(s) useful in the invention is less than20,000 poise as measured a 1 radian/second on a rotary melt rheometer at290° C.

In one embodiment, the melt viscosity of the polyester(s) useful infilm(s) and/or sheet(s) useful in the invention is less than 15,000poise as measured at 1 radian/second (rad/sec) on a rotary meltrheometer at 290° C. In one embodiment, the melt viscosity of thepolyester(s) useful in the film(s) and/or sheet(s) useful in theinvention is less than 10,000 poise as measured at 1 radian/second(rad/sec) on a rotary melt rheometer at 290° C. In another embodiment,the melt viscosity of the polyester(s) useful in the film(s) and/orsheet(s) useful in the invention is less than 6,000 poise as measured at1 radian/second on a rotary melt rheometer at 290° C. Viscosity atrad/sec is related to processability. Typical polymers have viscositiesof less than 10,000 poise as measured at 1 radian/second when measuredat their processing temperature. Polyesters are typically not processedabove 290C. Polycarbonate is typically processed at 290° C. Theviscosity at 1 rad/sec of a typical 12 melt flow rate polycarbonate is7000 poise at 290° C.

In one embodiment of the invention, the polyesters useful in the film(s)and/or sheet(s) useful in the invention exhibit superior notched Izodimpact strength in thick sections. Notched Izod impact strength, asdescribed in ASTM D256, is a common method of measuring toughness. Whentested by the Izod method, polymers can exhibit either a complete breakfailure mode, where the test specimen breaks into two distinct parts, ora partial or no break failure mode, where the test specimen remains asone part. The complete break failure mode is associated with low energyfailure. The partial and no break failure modes are associated with highenergy failure. A typical thickness used to measure Izod toughness is⅛″. At this thickness, very few polymers are believed to exhibit apartial or no break failure mode, polycarbonate being one notableexample. When the thickness of the test specimen is increased to ¼″,however, no commercial amorphous materials exhibit a partial or no breakfailure mode. In one embodiment, compositions of the present exampleexhibit a no break failure mode when tested in Izod using a ¼″ thickspecimen.

The present polyesters useful in this film(s) and/or sheet(s) useful inthe invention can possess one or more of the following properties: Inone embodiment, the polyesters useful in the film(s) and/or sheet(s)useful in the invention exhibit a notched Izod impact strength of atleast 150 J/m (3 ft-lb/in) at 23° C. with a 10-mil notch in a 3.2 mm(⅛-inch) thick bar determined according to ASTM D256; in one embodiment,the polyesters useful in the film(s) and/or sheet(s) useful in theinvention exhibit a notched Izod impact strength of at least (400 J/m)7.5 ft-lb/in at 23° C. with a 10-mil notch in a 3.2 mm (⅛-inch) thickbar determined according to ASTM D256; in one embodiment, the polyestersuseful in the film(s) and/or sheet(s) useful in the invention exhibit anotched Izod impact strength of at least 1000 J/m (18 ft-lb/in) at 23°C. with a 10-mil notch in a 3.2 mm (⅛-inch) thick bar determinedaccording to ASTM D256. In one embodiment, the polyesters useful in thefilm(s) and/or sheet(s) useful in the invention exhibit a notched Izodimpact strength of at least 150 J/m (3 ft-lb/in) at 23° C. with a 10-milnotch in a 6.4 mm (¼-inch) thick bar determined according to ASTM D256;in one embodiment, the polyesters useful in the film(s) and/or sheet(s)useful in the invention exhibit a notched Izod impact strength of atleast (400 J/m) 7.5 ft-lb/in at 23° C. with a 10-mil notch in a 6.4 mm(¼-inch) thick bar determined according to ASTM D256; in one embodiment,the polyesters useful in the film or sheet of the invention exhibit anotched Izod impact strength of at least 10 ft-lb/in at 23° C. with a10-mil notch in a ¼-inch thick bar determined according to ASTM D256; inone embodiment, the polyesters useful in the film(s) and/or sheet(s)useful in the invention exhibit a notched Izod impact strength of atleast 1000 J/m (18 ft-lb/in) at 23° C. with a 10-mil notch in a 6.4 mm(¼-inch) thick bar determined according to ASTM D256.

In another embodiment, certain polyesters useful in the film(s) and/orsheet(s) useful in the invention can exhibit an increase in notched Izodimpact strength when measured at 0° C. of at least 3% or at least 5% orat least 10% or at least 15% as compared to the notched Izod impactstrength when measured at −5° C. with a 10-mil notch in a ⅛-inch thickbar determined according to ASTM D256. In addition, certain otherpolyesters of the invention can also exhibit a retention of notched Izodimpact strength within plus or minus 5% when measured at 0° C. through30° C. with a 10-mil notch in a ⅛-inch thick bar determined according toASTM D256.

In yet another embodiment, certain polyesters useful in the film(s)and/or sheet(s) useful in the invention can exhibit a retention innotched Izod impact strength with a loss of no more than 70% whenmeasured at 23° C. with a 10-mil notch in a ¼-inch thick bar determinedaccording to ASTM D256 as compared to notched Izod impact strength forthe same polyester when measured at the same temperature with a 10-milnotch in a ⅛-inch thick bar determined according to ASTM D256.

In one embodiment, the polyesters useful in the film(s) and/or sheet(s)useful in the invention can exhibit a ductile-to-brittle transitiontemperature of less than 0° C. based on a 10-mil notch in a ⅛-inch thickbar as defined by ASTM D256.

In one embodiment, the polyesters useful in the film(s) and/or sheet(s)useful in the invention can exhibit at least one of the followingdensities as determined using a gradient density column at 23° C.: adensity of less than 1.2 g/ml at 23° C.; a density of less than 1.18g/ml at 23° C.; a density of 0.8 to 1.3 g/ml at 23° C.; a density of0.80 to 1.2 g/ml at 23° C.; a density of 0.80 to less than 1.2 g/ml at23° C.; a density of 1.0 to 1.3 g/ml at 23° C.; a density of 1.0 to 1.2g/ml at 23° C.; a density of 1.0 to 1.1 g/ml at 23° C.; a density of1.13 to 1.3 g/ml at 23° C.; a density of 1.13 to 1.2 g/ml at 23° C.

In one embodiment, the polyesters useful in film(s) and/or sheet(s)useful in this invention can be visually clear. The term “visuallyclear” is defined herein as an appreciable absence of cloudiness,haziness, and/or muddiness, when inspected visually. In anotherembodiment, when the polyesters are blended with polycarbonate,including, but not limited to, bisphenol A polycarbonates, the blendscan be visually clear.

In other embodiments of the invention, the polyesters useful in thefilm(s) and/or sheet(s) useful in the invention may have a yellownessindex (ASTM D-1925) of less than 50 or less than 20.

In one embodiment, the polyesters useful in the film(s) and/or sheet(s)useful in the invention and/or the polyester compositions of theinvention, with or without toners, can have color values L*, a* and b*which were determined using a Hunter Lab Ultrascan Spectra Colorimetermanufactured by Hunter Associates Lab Inc., Reston, Va. The colordeterminations are averages of values measured on either pellets of thepolyesters or plaques or other items injection molded or extruded fromthem. They are determined by the L*a*b* color system of the CIE(International Commission on Illumination) (translated), wherein L*represents the lightness coordinate, a* represents the red/greencoordinate, and b* represents the yellow/blue coordinate. In certainembodiments, the b* values for the polyesters useful in the inventioncan be from −10 to less than 10 and the L* values can be from 50 to 90.In other embodiments, the b* values for the polyesters useful in theinvention can be present in one of the following ranges: from: from −10to 9; −10 to 8; −10 to 7; −10 to 6; −10 to 5; −10 to 4; −10 to 3; −10 to2; from −5 to 9; −5 to 8; −5 to 7; −5 to 6; −5 to 5; −5 to 4; −5 to 3;−5 to 2; 0 to 9; 0 to 8; 0 to 7; 0 to 6; 0 to 5; 0 to 4; 0 to 3; 0 to 2;1 to 10; 1 to 9; 1 to 8; 1 to 7; 1 to 6; 1 to 5; 1 to 4; 1 to 3; and 1to 2. In other embodiments, the L* value for the polyesters useful inthe film(s) and/or sheet(s) useful in the invention can be present inone of the following ranges: 50 to 60; 50 to 70; 50 to 80; 50 to 90; 60to 70; 60 to 80; 60 to 90; 70 to 80; 79 to 90.

In some embodiments, use of the polyester compositions useful in thefilm(s) and/or sheet(s) useful in the invention minimizes and/oreliminates the drying step prior to melt processing and/orthermoforming.

The polyester portion of the polyester compositions useful in thefilm(s) and/or sheet(s) useful in the invention can be made by processesknown from the literature such as, for example, by processes inhomogenous solution, by transesterification processes in the melt, andby two phase interfacial processes. Suitable methods include, but arenot limited to, the steps of reacting one or more dicarboxylic acidswith one or more glycols at a temperature of 100° C. to 315° C. at apressure of 0.1 to 760 mm Hg for a time sufficient to form a polyester.See U.S. Pat. No. 3,772,405 for methods of producing polyesters, thedisclosure regarding such methods is hereby incorporated herein byreference.

In another aspect, the invention relates to a process for producingpolyesters useful in the polyester compositions of the film(s) and/orsheet(s) useful in the invention. The process comprises:

(I) heating a mixture comprising the monomers useful in any of thepolyesters useful in the invention in the presence of a catalyst at atemperature of 150 to 240° C. for a time sufficient to produce aninitial polyester;

(II) heating the initial polyester of step (I) at a temperature of 240to 320° C. for 1 to 4 hours; and

(III) removing any unreacted glycols.

Suitable catalysts for use in this process include, but are not limitedto, organo-zinc or tin compounds. The use of this type of catalyst iswell known in the art. Examples of catalysts useful in the presentinvention include, but are not limited to, zinc acetate, butyltintris-2-ethylhexanoate, dibutyltin diacetate, and/or dibutyltin oxide.Other catalysts may include, but are not limited to, those based ontitanium, zinc, manganese, lithium, germanium, and cobalt. Catalystamounts can range from 10 ppm to 20,000 ppm or 10 to 10,000 ppm, or 10to 5000 ppm or 10 to 1000 ppm or 10 to 500 ppm, or 10 to 300 ppm or 10to 250 based on the catalyst metal and based on the weight of the finalpolymer. The process can be carried out in either a batch or continuousprocess.

Typically, step (I) can be carried out until 50% by weight or more ofthe 2,2,4,4-tetramethyl-1,3-cyclobutanediol has been reacted. Step (I)may be carried out under pressure, ranging from atmospheric pressure to100 psig. The term “reaction product” as used in connection with any ofthe catalysts useful in the invention refers to any product of apolycondensation or esterification reaction with the catalyst and any ofthe monomers used in making the polyester as well as the product of apolycondensation or esterification reaction between the catalyst and anyother type of additive.

Typically, Step (II) and Step (III) can be conducted at the same time.These steps can be carried out by methods known in the art such as byplacing the reaction mixture under a pressure ranging from 0.002 psig tobelow atmospheric pressure, or by blowing hot nitrogen gas over themixture.

The invention further relates to a polyester product made by the processdescribed above.

The invention further relates to a polymer blend. The blend comprises:

(a) 5 to 95 weight % of at least one of the polyesters described above;and

(b) 5 to 95 weight % of at least one of the polymeric components.

Suitable examples of the polymeric components include, but are notlimited to, polyamides such as nylon; other polyesters different thanthose described herein; ZYTEL® from DuPont; polystyrene; polystyrenecopolymers; styrene acrylonitrile copolymers; acrylonitrile butadienestyrene copolymers; poly(methylmethacrylate); acrylic copolymers;poly(ether-imides) such as ULTEM® (a poly(ether-imide) from GeneralElectric); polyphenylene oxides such as poly(2,6-dimethylphenyleneoxide) or poly(phenylene oxide)/polystyrene blends such as NORYL 1000®(a blend of poly(2,6-dimethylphenylene oxide) and polystyrene resinsfrom General Electric); polyphenylene sulfides; polyphenylenesulfide/sulfones; poly(ester-carbonates); polycarbonates such as LEXAN®(a polycarbonate from General Electric); polysulfones; polysulfoneethers; and poly(ether-ketones) of aromatic dihydroxy compounds; ormixtures of any of the foregoing polymers. The blends can be prepared byconventional processing techniques known in the art, such as meltblending or solution blending. In one embodiment, polycarbonate is notpresent in the polyester composition. If polycarbonate is used in ablend in the polyester compositions of the film(s) and/or sheet(s)useful in the invention, the blends can be visually clear. The polyestercompositions useful in the film(s) and/or sheet(s) useful in theinvention also contemplate the exclusion of polycarbonate as well as theinclusion of polycarbonate.

Polycarbonates useful in the film(s) and/or sheet(s) useful in theinvention may be prepared according to known procedures, for example, byreacting the dihydroxyaromatic compound with a carbonate precursor suchas phosgene, a haloformate or a carbonate ester, a molecular weightregulator, an acid acceptor and a catalyst. Methods for preparingpolycarbonates are known in the art and are described, for example, inU.S. Pat. No. 4,452,933, where the disclosure regarding the preparationof polycarbonates is hereby incorporated by reference herein.

Examples of suitable carbonate precursors include, but are not limitedto, carbonyl bromide, carbonyl chloride, or mixtures thereof; diphenylcarbonate; a di(halophenyl)carbonate, e.g., di(trichlorophenyl)carbonate, di(tribromophenyl) carbonate, and the like;di(alkylphenyl)carbonate, e.g., di(tolyl)carbonate;di(naphthyl)carbonate; di(chloronaphthyl)carbonate, or mixtures thereof;and bis-haloformates of dihydric phenols.

Examples of suitable molecular weight regulators include, but are notlimited to, phenol, cyclohexanol, methanol, alkylated phenols, such asoctylphenol, para-tertiary-butyl-phenol, and the like. In oneembodiment, the molecular weight regulator is phenol or an alkylatedphenol.

The acid acceptor may be either an organic or an inorganic acidacceptor. A suitable organic acid acceptor can be a tertiary amine andincludes, but is not limited to, such materials as pyridine,triethylamine, dimethylaniline, tributylamine, and the like. Theinorganic acid acceptor can be either a hydroxide, a carbonate, abicarbonate, or a phosphate of an alkali or alkaline earth metal.

The catalysts that can be used include, but are not limited to, thosethat typically aid the polymerization of the monomer with phosgene.Suitable catalysts include, but are not limited to, tertiary amines suchas triethylamine, tripropylamine, N,N-dimethylaniline, quaternaryammonium compounds such as, for example, tetraethylammonium bromide,cetyl triethyl ammonium bromide, tetra-n-heptylammonium iodide,tetra-n-propyl ammonium bromide, tetramethyl ammonium chloride,tetra-methyl ammonium hydroxide, tetra-n-butyl ammonium iodide,benzyltrimethyl ammonium chloride and quaternary phosphonium compoundssuch as, for example, n-butyltriphenyl phosphonium bromide andmethyltriphenyl phosphonium bromide.

The polycarbonates useful in the polyester compositions of the film(s)and/or sheet(s) useful in the invention also may becopolyestercarbonates such as those described in U.S. Pat. Nos.3,169,121; 3,207,814; 4,194,038; 4,156,069; 4,430,484,4,465,820, and4,981,898, where the disclosure regarding copolyestercarbonates fromeach of the U.S. Patents is incorporated by reference herein.

Copolyestercarbonates useful in film(s) and/or sheet(s) useful in theinvention can be available commercially or can be prepared by knownmethods in the art. For example, they can be typically obtained by thereaction of at least one dihydroxyaromatic compound with a mixture ofphosgene and at least one dicarboxylic acid chloride, especiallyisophthaloyl chloride, terephthaloyl chloride, or both.

In addition, the polyester compositions and the polymer blendcompositions containing the polyesters of film(s) and/or sheet(s) usefulin the invention may also contain from 0.01 to 25% by weight or 0.01 to20% by weight or 0.01 to 15% by weight or 0.01 to 10% by weight or 0.01to 5% by weight of the total weight of the polyester composition ofcommon additives such as colorants, dyes, mold release agents, flameretardants, plasticizers, nucleating agents, stabilizers, including butnot limited to, UV stabilizers, thermal stabilizers and/or reactionproducts thereof, fillers, and impact modifiers. Examples of typicalcommercially available impact modifiers well known in the art and usefulin this invention include, but are not limited to, ethylene/propyleneterpolymers; functionalized polyolefins, such as those containing methylacrylate and/or glycidyl methacrylate; styrene-based block copolymericimpact modifiers; and various acrylic core/shell type impact modifiers.For example, UV additives can be incorporated into articles ofmanufacture through addition to the bulk, through application of a hardcoat, or through coextrusion of a cap layer. Residues of such additivesare also contemplated as part of the polyester composition.

The polyesters useful in the film(s) and/or sheet(s) useful in theinvention can comprise at least one chain extender. Suitable chainextenders include, but are not limited to, multifunctional (including,but not limited to, bifunctional) isocyanates, multifunctional epoxides,including for example, epoxylated novolacs, and phenoxy resins. Incertain embodiments, chain extenders may be added at the end of thepolymerization process or after the polymerization process. If addedafter the polymerization process, chain extenders can be incorporated bycompounding or by addition during conversion processes such as injectionmolding or extrusion. The amount of chain extender used can varydepending on the specific monomer composition used and the physicalproperties desired but is generally about 0.1 percent by weight to about10 percent by weight, preferably about 0.1 to about 5 percent by weight,based on the total weight of the polyester.

Thermal stabilizers are compounds that stabilize polyesters duringpolyester manufacture and/or post polymerization, including, but notlimited to, phosphorous compounds including but not limited tophosphoric acid, phosphorous acid, phosphonic acid, phosphinic acid,phosphonous acid, and various esters and salts thereof. These can bepresent in the polyester compositions useful in the film(s) and/orsheet(s) useful in the invention. The esters can be alkyl, branchedalkyl, substituted alkyl, difunctional alkyl, alkyl ethers, aryl, andsubstituted aryl. In one embodiment, the number of ester groups presentin the particular phosphorous compound can vary from zero up to themaximum allowable based on the number of hydroxyl groups present on thethermal stabilizer used. The term “thermal stabilizer” is intended toinclude the reaction product(s) thereof. The term “reaction product” asused in connection with the thermal stabilizers useful in the polyestersuseful in the invention refers to any product of a polycondensation oresterification reaction between the thermal stabilizer and any of themonomers used in making the polyester as well as the product of apolycondensation or esterification reaction between the catalyst and anyother type of additive.

Reinforcing materials may be useful in the compositions useful infilm(s) and/or sheet(s) useful in the invention. The reinforcingmaterials may include, but are not limited to, carbon filaments,silicates, mica, clay, talc, titanium dioxide, Wollastonite, glassflakes, glass beads and fibers, and polymeric fibers and combinationsthereof. In one embodiment, the reinforcing materials are glass, suchas, fibrous glass filaments, mixtures of glass and talc, glass and mica,and glass and polymeric fibers.

In another embodiment, the invention further relates to articles ofmanufacture comprising the film(s) and/or sheet(s) containing polyestercompositions described herein.

The films and/or sheets useful in the present invention can be of anythickness which would be apparent to one of ordinary skill in the art.In one embodiment, the film(s) of the invention have a thickness of nomore than 40 mils. In one embodiment, the film(s) of the invention havea thickness of no more than 35 mils. In one embodiment, the film(s) ofthe invention have a thickness of no more than 30 mils. In oneembodiment, the film(s) of the invention have a thickness of no morethan 25 mils. In one embodiment, the film(s) of the invention have athickness of no more than 20 mils.

In one embodiment, the sheet(s) of the invention have a thickness of noless than 20 mils. In another embodiment, the sheet(s) of the inventionhave a thickness of no less than 25 mils. In another embodiment, thesheet(s) of the invention have a thickness of no less than 30 mils. Inanother embodiment, the sheet(s) of the invention have a thickness of noless than 35 mils. In another embodiment, the sheet(s) of the inventionhave a thickness of no less than 40 mils.

The invention further relates to the film(s) and/or sheet(s) comprisingthe polyester compositions of the invention. The methods of forming thepolyesters into film(s) and/or sheet(s) are well known in the art.Examples of film(s) and/or sheet(s) of the invention including but notlimited to extruded film(s) and/or sheet(s), calendered film(s) and/orsheet(s), compression molded film(s) and/or sheet(s), solution castedfilm(s) and/or sheet(s). Methods of making film and/or sheet include butare not limited to extrusion, calendering, compression molding, andsolution casting.

Examples of potential articles made from film and/or sheet include, butare not limited, to uniaxially stretched film, biaxially stretched film,shrink film (whether or not uniaxially or biaxially stretched), liquidcrystal display film (including, but not limited to, diffuser sheets,compensation films and protective films), thermoformed sheet, graphicarts film, outdoor signs, skylights, painted articles, laminates,laminated articles, and/or multiwall films or sheets.

Examples of graphic arts film include, but are not limited to,nameplates, membrane switch overlays; point-of-purchase displays; flator in-mold decorative panels on washing machines; flat touch panels onrefrigerators; flat panel on ovens; decorative interior trim forautomobiles; instrument clusters for automobiles; cell phone covers;heating and ventilation control displays; automotive console panels;automotive gear shift panels; control displays or warning signals forautomotive instrument panels; facings, dials or displays on householdappliances; facings, dials or displays on washing machines; facings,dials or displays on dishwashers; keypads for electronic devices;keypads for mobile phones, PDAs (hand-held computers) or remotecontrols; displays for electronic devices; displays for hand-heldelectronic devices such as phones and PDAs; panels and housings formobile or standard phones; logos on electronic devices; and logos forhand-held phones.

Multiwall film or sheet refers to sheet extruded as a profile consistingof multiple layers that are connected to each other by means of verticalribs. Examples of multiwall film or sheet include but are not limited togreenhouses and commercial canopies.

For purposes of this disclosure, the term “wt.” means “weight”.

The following examples further illustrate how the polyester compositionsuseful in the film(s) and/or sheet(s) and methods of making thepolyester compositions and evaluations thereof, and are intended to bepurely exemplary of the invention and are not intended to limit thescope thereof. Unless indicated otherwise, parts are parts by weight,temperature is in degrees C. or is at room temperature, and pressure isat or near atmospheric.

EXAMPLES

Measurement Methods

The inherent viscosity of the polyesters was determined in 60/40 (wt/wt)phenol/tetrachloroethane at a concentration of 0.5 g/100 ml at 25° C.

Unless stated otherwise, the glass transition temperature (T_(g)) wasdetermined using a TA DSC 2920 instrument from Thermal AnalystInstruments at a scan rate of 20° C./min according to ASTM D3418.

The glycol content and the cis/trans ratio of the compositions weredetermined by proton nuclear magnetic resonance (NMR) spectroscopy. AllNMR spectra were recorded on a JEOL Eclipse Plus 600 MHz nuclearmagnetic resonance spectrometer using either chloroform-trifluoroaceticacid (70-30 volume/volume) for polymers or, for oligomeric samples,60/40(wt/wt) phenol/tetrachloroethane with deuterated chloroform addedfor lock. Peak assignments for 2,2,4,4-tetramethyl-1,3-cyclobutanediolresonances were made by comparison to model mono- and dibenzoate estersof 2,2,4,4-tetramethyl-1,3-cyclobutanediol. These model compoundsclosely approximate the resonance positions found in the polymers andoligomers.

The crystallization half-time, t½, was determined by measuring the lighttransmission of a sample via a laser and photo detector as a function oftime on a temperature controlled hot stage. This measurement was done byexposing the polymers to a temperature, T_(max), and then cooling it tothe desired temperature. The sample was then held at the desiredtemperature by a hot stage while transmission measurements were made asa function of time. Initially, the sample was visually clear with highlight transmission and became opaque as the sample crystallized. Thecrystallization half-time was recorded as the time at which the lighttransmission was halfway between the initial transmission and the finaltransmission. T_(max) is defined as the temperature required to melt thecrystalline domains of the sample (if crystalline domains are present).The T_(max) reported in the examples below represents the temperature atwhich each sample was heated to condition the sample prior tocrystallization half time measurement. The T_(max) temperature isdependant on composition and is typically different for each polyester.For example, PCT may need to be heated to some temperature greater than290° C. to melt the crystalline domains.

Density was determined using a gradient density column at 23° C.

The melt viscosity reported herein was measured by using a RheometricsDynamic Analyzer (RDA II). The melt viscosity was measured as a functionof shear rate, at frequencies ranging from 1 to 400 rad/sec, at thetemperatures reported. The zero shear melt viscosity (η_(o)) is the meltviscosity at zero shear rate estimated by extrapolating the data byknown models in the art. This step is automatically performed by theRheometrics Dynamic Analyzer (RDA II) software.

The polymers were dried at a temperature ranging from 80 to 100° C. in avacuum oven for 24 hours and injection molded on a Boy 22S moldingmachine to give ⅛×½×5-inch and ¼×½×5-inch flexure bars. These bars werecut to a length of 2.5 inch and notched down the ½ inch width with a10-mil notch in accordance with ASTM D256. The average Izod impactstrength at 23° C. was determined from measurements on 5 specimens.

In addition, 5 specimens were tested at various temperatures using 5° C.increments in order to determine the brittle-to-ductile transitiontemperature. The brittle-to-ductile transition temperature is defined asthe temperature at which 50% of the specimens fail in a brittle manneras denoted by ASTM D256.

Color values reported herein were determined using a Hunter LabUltrascan Spectra Colorimeter manufactured by Hunter Associates LabInc., Reston, Va. The color determinations were averages of valuesmeasured on either pellets of the polyesters or plaques or other itemsinjection molded or extruded from them. They were determined by theL*a*b* color system of the CIE (International Commission onIllumination) (translated), wherein L* represents the lightnesscoordinate, a* represents the red/green coordinate, and b* representsthe yellow/blue coordinate.

In addition, 10-mil films were compression molded using a Carver pressat 240° C.

Unless otherwise specified, the cis/trans ratio of the 1,4cyclohexanedimethanol used in the following examples was approximately30/70, and could range from 35/65 to 25/75. Unless otherwise specified,the cis/trans ratio of the 2,2,4,4-tetramethyl-1,3-cyclobutanediol usedin the following examples was approximately 50/50.

The following abbreviations apply throughout the working examples andfigures:

TPA Terephthalic acid DMT Dimethyl terephthalate TMCD2,2,4,4-tetramethyl-1,3-cyclobutanediol CHDM 1,4-cyclohexanedimethanolIV Inherent viscosity η₀ Zero shear melt viscosity T_(g) Glasstransition temperature T_(bd) Brittle-to-ductile transition temperatureT_(max) Conditioning temperature for crystallization half timemeasurements

Example 1

This example illustrates that 2,2,4,4-tetramethyl-1,3-cyclobutanediol ismore effective at reducing the crystallization rate of PCT than ethyleneglycol or isophthalic acid. In addition, this example illustrates thebenefits of 2,2,4,4-tetramethyl-1,3-cyclobutanediol on the glasstransition temperature and density.

A variety of copolyesters were prepared as described below. Thesecopolyesters were all made with 200 ppm dibutyl tin oxide as thecatalyst in order to minimize the effect of catalyst type andconcentration on nucleation during crystallization studies. Thecis/trans ratio of the 1,4-cyclohexanedimethanol was 31/69 while thecis/trans ratio of the 2,2,4,4-tetramethyl-1,3-cyclobutanediol isreported in Table 1.

For purposes of this example, the samples had sufficiently similarinherent viscosities thereby effectively eliminating this as a variablein the crystallization rate measurements.

Crystallization half-time measurements from the melt were made attemperatures from 140 to 200° C. at 10° C. increments and are reportedin Table 1. The fastest crystallization half-time for each sample wastaken as the minimum value of crystallization half-time as a function oftemperature, typically occurring around 170 to 180° C. The fastestcrystallization half-times for the samples are plotted in FIG. 1 as afunction of mole % comonomer modification to PCT.

The data shows that 2,2,4,4-tetramethyl-1,3-cyclobutanediol is moreeffective than ethylene glycol and isophthalic acid at decreasing thecrystallization rate (i.e., increasing the crystallization half-time).In addition, 2,2,4,4-tetramethyl-1,3-cyclobutanediol increases T_(g) andlowers density.

TABLE 1 Crystallization Half-times (min) at at at at at at at ComonomerIV Density T_(g) T_(max) 140° C. 150° C. 160° C. 170° C. 180° C. 190° C.200° C. Example (mol %)¹ (dl/g) (g/ml) (° C.) (° C.) (min) (min) (min)(min) (min) (min) (min) 1A 20.2% A² 0.630 1.198 87.5 290 2.7 2.1 1.3 1.20.9 1.1 1.5 1B 19.8% B 0.713 1.219 87.7 290 2.3 2.5 1.7 1.4 1.3 1.4 1.71C 20.0% C 0.731 1.188 100.5 290 >180 >60 35.0 23.3 21.7 23.3 25.2 1D40.2% A² 0.674 1.198 81.2 260 18.7 20.0 21.3 25.0 34.0 59.9 96.1 1E34.5% B 0.644 1.234 82.1 260 8.5 8.2 7.3 7.3 8.3 10.0 11.4 1F 40.1% C0.653 1.172 122.0 260 >10 days >5 days >5 days 19204 >5 days >5 days >5days 1G 14.3% D 0.646³ 1.188 103.0 290 55.0 28.8 11.6 6.8 4.8 5.0 5.5 1H15.0% E 0.728⁴ 1.189 99.0 290 25.4 17.1 8.1 5.9 4.3 2.7 5.1 ¹The balanceof the diol component of the polyesters in Table 1 is1,4-cyclohexanedimethanol; and the balance of the dicarboxylic acidcomponent of the polyesters in Table 1 is dimethyl terephthalate; if thedicarboxylic acid is not described, it is 100 mole % dimethylterephthalate. ²100 mole % 1,4-cyclohexanedimethanol. ³A film waspressed from the ground polyester of Example 1G at 240° C. The resultingfilm had an inherent viscosity value of 0.575 dL/g. ⁴A film was pressedfrom the ground polyester of Example 1H at 240° C. The resulting filmhad an inherent viscosity value of 0.0.652 dL/g. where: A is IsophthalicAcid B is Ethylene Glycol C is 2,2,4,4-Tetramethyl-1,3-cyclobutanediol(approx. 50/50 cis/trans) D is 2,2,4,4-Tetramethyl-1,3-cyclobutanediol(98/2 cis/trans) E is 2,2,4,4-Tetramethyl-1,3-cyclobutanediol (5/95cis/trans)

As shown in Table 1 and FIG. 1, 2,2,4,4-tetramethyl-1,3-cyclobutanediolis more effective than other comonomers, such ethylene glycol andisophthalic acid, at increasing the crystallization half-time, i.e., thetime required for a polymer to reach half of its maximum crystallinity.By decreasing the crystallization rate of PCT (increasing thecrystallization half-time), amorphous articles based on2,2,4,4-tetramethyl-1,3-cyclobutanediol-modified PCT as described hereinmay be fabricated by methods known in the art. As shown in Table 1,these materials can exhibit higher glass transition temperatures andlower densities than other modified PCT copolyesters.

Preparation of the polyesters shown on Table 1 is described below.

Example 1A

This example illustrates the preparation of a copolyester with a targetcomposition of 80 mol % dimethyl terephthalate residues, 20 mol %dimethyl isophthalate residues, and 100 mol % 1,4-cyclohexanedimethanolresidues (28/72 cis/trans).

A mixture of 56.63 g of dimethyl terephthalate, 55.2 g of1,4-cyclohexanedimethanol, 14.16 g of dimethyl isophthalate, and 0.0419g of dibutyl tin oxide was placed in a 500-milliliter flask equippedwith an inlet for nitrogen, a metal stirrer, and a short distillationcolumn. The flask was placed in a Wood's metal bath already heated to210° C. The stirring speed was set to 200 RPM throughout the experiment.The contents of the flask were heated at 210° C. for 5 minutes and thenthe temperature was gradually increased to 290° C. over 30 minutes. Thereaction mixture was held at 290° C. for 60 minutes and then vacuum wasgradually applied over the next 5 minutes until the pressure inside theflask reached 100 mm of Hg. The pressure inside the flask was furtherreduced to 0.3 mm of Hg over the next 5 minutes. A pressure of 0.3 mm ofHg was maintained for a total time of 90 minutes to remove excessunreacted diols. A high melt viscosity, visually clear and colorlesspolymer was obtained with a glass transition temperature of 87.5° C. andan inherent viscosity of 0.63 dl/g. NMR analysis showed that the polymerwas composed of 100 mol % 1,4-cyclohexanedimethanol residues and 20.2mol % dimethyl isophthalate residues.

Example 1B

This example illustrates the preparation of a copolyester with a targetcomposition of 100 mol % dimethyl terephthalate residues, 20 mol %ethylene glycol residues, and 80 mol % 1,4-cyclohexanedimethanolresidues (32/68 cis/trans).

A mixture of 77.68 g of dimethyl terephthalate, 50.77 g of1,4-cyclohexanedimethanol, 27.81 g of ethylene glycol, and 0.0433 g ofdibutyl tin oxide was placed in a 500-milliliter flask equipped with aninlet for nitrogen, a metal stirrer, and a short distillation column.The flask was placed in a Wood's metal bath already heated to 200° C.The stirring speed was set to 200 RPM throughout the experiment. Thecontents of the flask were heated at 200° C. for 60 minutes and then thetemperature was gradually increased to 210° C. over 5 minutes. Thereaction mixture was held at 210° C. for 120 minutes and then heated upto 280° C. in 30 minutes. Once at 280° C., vacuum was gradually appliedover the next 5 minutes until the pressure inside the flask reached 100mm of Hg. The pressure inside the flask was further reduced to 0.3 mm ofHg over the next 10 minutes. A pressure of 0.3 mm of Hg was maintainedfor a total time of 90 minutes to remove excess unreacted diols. A highmelt viscosity, visually clear and colorless polymer was obtained with aglass transition temperature of 87.7° C. and an inherent viscosity of0.71 dl/g. NMR analysis showed that the polymer was composed of 19.8 mol% ethylene glycol residues.

Example 1C

This example illustrates the preparation of a copolyester with a targetcomposition of 100 mol % dimethyl terephthalate residues, 20 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues, and 80 mol %1,4-cyclohexanedimethanol residues (31/69 cis/trans).

A mixture of 77.68 g of dimethyl terephthalate, 48.46 g of1,4-cyclohexanedimethanol, 17.86 g of2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 0.046 g of dibutyl tinoxide was placed in a 500-milliliter flask equipped with an inlet fornitrogen, a metal stirrer, and a short distillation column. Thispolyester was prepared in a manner similar to that described in Example1A. A high melt viscosity, visually clear and colorless polymer wasobtained with a glass transition temperature of 100.5° C. and aninherent viscosity of 0.73 dl/g. NMR analysis showed that the polymerwas composed of 80.5 mol % 1,4-cyclohexanedimethanol residues and 19.5mol % 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.

Example 1D

This example illustrates the preparation of a copolyester with a targetcomposition of 100 mol % dimethyl terephthalate residues, 40 mol %dimethyl isophthalate residues, and 100 mol % 1,4-cyclohexanedimethanolresidues (28/72 cis/trans).

A mixture of 42.83 g of dimethyl terephthalate, 55.26 g of1,4-cyclohexanedimethanol, 28.45 g of dimethyl isophthalate, and 0.0419g of dibutyl tin oxide was placed in a 500-milliliter flask equippedwith an inlet for nitrogen, a metal stirrer, and a short distillationcolumn. The flask was placed in a Wood's metal bath already heated to210° C. The stirring speed was set to 200 RPM throughout the experiment.The contents of the flask were heated at 210° C. for 5 minutes and thenthe temperature was gradually increased to 290° C. over 30 minutes. Thereaction mixture was held at 290° C. for 60 minutes and then vacuum wasgradually applied over the next 5 minutes until the pressure inside theflask reached 100 mm of Hg. The pressure inside the flask was furtherreduced to 0.3 mm of Hg over the next 5 minutes. A pressure of 0.3 mm ofHg was maintained for a total time of 90 minutes to remove excessunreacted diols. A high melt viscosity, visually clear and colorlesspolymer was obtained with a glass transition temperature of 81.2° C. andan inherent viscosity of 0.67 dl/g. NMR analysis showed that the polymerwas composed of 100 mol % 1,4-cyclohexanedimethanol residues and 40.2mol % dimethyl isophthalate residues.

Example 1E

This example illustrates the preparation of a copolyester with a targetcomposition of 100 mol % dimethyl terephthalate residues, 40 mol %ethylene glycol residues, and 60 mol % 1,4-cyclohexanedimethanolresidues (31/69 cis/trans).

A mixture of 81.3 g of dimethyl terephthalate, 42.85 g of1,4-cyclohexanedimethanol, 34.44 g of ethylene glycol, and 0.0419 g ofdibutyl tin oxide was placed in a 500-milliliter flask equipped with aninlet for nitrogen, a metal stirrer, and a short distillation column.The flask was placed in a Wood's metal bath already heated to 200° C.The stirring speed was set to 200 RPM throughout the experiment. Thecontents of the flask were heated at 200° C. for 60 minutes and then thetemperature was gradually increased to 210° C. over 5 minutes. Thereaction mixture was held at 210° C. for 120 minutes and then heated upto 280° C. in 30 minutes. Once at 280° C., vacuum was gradually appliedover the next 5 minutes until the pressure inside the flask reached 100mm of Hg. The pressure inside the flask was further reduced to 0.3 mm ofHg over the next 10 minutes. A pressure of 0.3 mm of Hg was maintainedfor a total time of 90 minutes to remove excess unreacted diols. A highmelt viscosity, visually clear and colorless polymer was obtained with aglass transition temperature of 82.1° C. and an inherent viscosity of0.64 dl/g. NMR analysis showed that the polymer was composed of 34.5 mol% ethylene glycol residues.

Example 1F

This example illustrates the preparation of a copolyester with a targetcomposition of 100 mol % dimethyl terephthalate residues, 40 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues, and 60 mol %1,4-cyclohexanedimethanol residues (31/69 cis/trans).

A mixture of 77.4 g of dimethyl terephthalate, 36.9 g of1,4-cyclohexanedimethanol, 32.5 g of2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 0.046 g of dibutyl tinoxide was placed in a 500-milliliter flask equipped with an inlet fornitrogen, a metal stirrer, and a short distillation column. The flaskwas placed in a Wood's metal bath already heated to 210° C. The stirringspeed was set to 200 RPM throughout the experiment. The contents of theflask were heated at 210° C. for 3 minutes and then the temperature wasgradually increased to 260° C. over 30 minutes. The reaction mixture washeld at 260° C. for 120 minutes and then heated up to 290° C. in 30minutes. Once at 290° C., vacuum was gradually applied over the next 5minutes until the pressure inside the flask reached 100 mm of Hg. Thepressure inside the flask was further reduced to 0.3 mm of Hg over thenext 5 minutes. A pressure of 0.3 mm of Hg was maintained for a totaltime of 90 minutes to remove excess unreacted diols. A high meltviscosity, visually clear and colorless polymer was obtained with aglass transition temperature of 122° C. and an inherent viscosity of0.65 dl/g. NMR analysis showed that the polymer was composed of 59.9 mol% 1,4-cyclohexanedimethanol residues and 40.1 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.

Example 1G

This example illustrates the preparation of a copolyester with a targetcomposition of 100 mol % dimethyl terephthalate residues, 20 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues (98/2 cis/trans), and80 mol % 1,4-cyclohexanedimethanol residues (31/69 cis/trans).

A mixture of 77.68 g of dimethyl terephthalate, 48.46 g of1,4-cyclohexaned imethanol, 20.77 g of2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 0.046 g of dibutyl tinoxide was placed in a 500-milliliter flask equipped with an inlet fornitrogen, a metal stirrer, and a short distillation column. The flaskwas placed in a Wood's metal bath already heated to 210° C. The stirringspeed was set to 200 RPM throughout the experiment. The contents of theflask were heated at 210° C. for 3 minutes and then the temperature wasgradually increased to 260° C. over 30 minutes. The reaction mixture washeld at 260° C. for 120 minutes and then heated up to 290° C. in 30minutes. Once at 290° C., vacuum was gradually applied over the next 5minutes until the pressure inside the flask reached 100 mm of Hg and thestirring speed was also reduced to 100 RPM. The pressure inside theflask was further reduced to 0.3 mm of Hg over the next 5 minutes andthe stirring speed was reduced to 50 RPM. A pressure of 0.3 mm of Hg wasmaintained for a total time of 60 minutes to remove excess unreacteddiols. A high melt viscosity, visually clear and colorless polymer wasobtained with a glass transition temperature of 103° C. and an inherentviscosity of 0.65 dl/g. NMR analysis showed that the polymer wascomposed of 85.7 mol % 1,4-cyclohexanedimethanol residues and 14.3 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.

Example 1H

This example illustrates the preparation of a copolyester with a targetcomposition of 100 mol % dimethyl terephthalate residues, 20 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues (5/95 cis/trans), and80 mol % 1,4-cyclohexanedimethanol residues (31/69 cis/trans).

A mixture of 77.68 g of dimethyl terephthalate, 48.46 g of1,4-cyclohexanedimethanol, 20.77 g of2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 0.046 g of dibutyl tinoxide was placed in a 500-milliliter flask equipped with an inlet fornitrogen, a metal stirrer, and a short distillation column. The flaskwas placed in a Wood's metal bath already heated to 210° C. The stirringspeed was set to 200 RPM at the beginning of the experiment. Thecontents of the flask were heated at 210° C. for 3 minutes and then thetemperature was gradually increased to 260° C. over 30 minutes. Thereaction mixture was held at 260° C. for 120 minutes and then heated upto 290° C. in 30 minutes. Once at 290° C., vacuum was gradually appliedover the next 5 minutes with a set point of 100 mm of Hg and thestirring speed was also reduced to 100 RPM. The pressure inside theflask was further reduced to a set point of 0.3 mm of Hg over the next 5minutes and the stirring speed was reduced to 50 RPM. This pressure wasmaintained for a total time of 60 minutes to remove excess unreacteddiols. It was noted that the vacuum system failed to reach the set pointmentioned above, but produced enough vacuum to produce a high meltviscosity, visually clear and colorless polymer with a glass transitiontemperature of 99° C. and an inherent viscosity of 0.73 dl/g. NMRanalysis showed that the polymer was composed of 85 mol %1,4-cyclohexanedimethanol residues and 15 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.

Example 2

This example illustrates that 2,2,4,4-tetramethyl-1,3-cyclobutanediolimproves the toughness of PCT-based copolyesters (polyesters containingterephthalic acid and 1,4-cyclohexanedimethanol).

Copolyesters based on 2,2,4,4-tetramethyl-1,3-cyclobutanediol wereprepared as described below. The cis/trans ratio of the1,4-cyclohexanedimethanol was approximately 31/69 for all samples.Copolyesters based on ethylene glycol and 1,4-cyclohexanedimethanol werecommercial polyesters. The copolyester of Example 2A (Eastar PCTG 5445)was obtained from Eastman Chemical Co. The copolyester of Example 2B wasobtained from Eastman Chemical Co. under the trade name Spectar. Example2C and Example 2D were prepared on a pilot plant scale (each a 15-lbbatch) following an adaptation of the procedure described in Example 1Aand having the inherent viscosities and glass transition temperaturesdescribed in Table 2 below. Example 2C was prepared with a target tinamount of 300 ppm (Dibutyltin Oxide). The final product contained 295ppm tin. The color values for the polyester of Example 2C were L*=77.11;a*=−1.50; and b*=5.79. Example 2D was prepared with a target tin amountof 300 ppm (Dibutyltin Oxide). The final product contained 307 ppm tin.The color values for the polyester of Example 2D were L*=66.72;a*=−1.22; and b*=16.28.

Materials were injection molded into bars and subsequently notched forIzod testing. The notched Izod impact strengths were obtained as afunction of temperature and are also reported in Table 2.

For a given sample, the Izod impact strength undergoes a majortransition in a short temperature span. For instance, the Izod impactstrength of a copolyester based on 38 mol % ethylene glycol undergoesthis transition between 15 and 20° C. This transition temperature isassociated with a change in failure mode; brittle/low energy failures atlower temperatures and ductile/high energy failures at highertemperatures. The transition temperature is denoted as thebrittle-to-ductile transition temperature, Tbd, and is a measure oftoughness. Tbd is reported in Table 2 and plotted against mol %comonomer in FIG. 2.

The data shows that adding 2,2,4,4-tetramethyl-1,3-cyclobutanediol toPCT lowers T_(bd) and improves the toughness, as compared to ethyleneglycol, which increases T_(bd) of PCT.

TABLE 2 Notched Izod Impact Energy (ft-lb/in) Comonomer IV T_(g) T_(bd)at at at at at at at at at at Example (mol %)¹ (dl/g) (° C.) (° C.) at−20° C. −15° C. −10° C. −5° C. 0° C. 5° C. 10° C. 15° C. 20° C. 25° C.30° C. 2A 38.0% B 0.68 86 18 NA NA NA 1.5 NA NA 1.5 1.5 32   32   NA 2B69.0% B 0.69 82 26 NA NA NA NA NA NA 2.1 NA 2.4 13.7 28.7 2C 22.0% C0.66 106 −5 1.5 NA 12 23   23 NA 23   NA NA NA NA 2D 42.8% C 0.60 133−12 2.5 2.5 11 NA 14 NA NA NA NA NA NA ¹The balance of the glycolcomponent of the polyesters in the Table is 1,4-cyclohexanedimethanol.All polymers were prepared from 100 mole % dimethyl terephthalate. NA =Not available. where: B is Ethylene glycol C is2,2,4,4-Tetramethyl-1,3-cyclobutanediol (50/50 cis/trans)

Example 3

This example illustrates that 2,2,4,4-tetramethyl-1,3-cyclobutanediolcan improve the toughness of PCT-based copolyesters(polyesterscontaining terephthalic acid and 1,4-cyclohexanedimethanol). Polyestersprepared in this example comprise from 15 to 25 mol % of2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.

Copolyesters based on dimethyl terephthalate,2,2,4,4-tetramethyl-1,3-cyclobutanediol , and 1,4-cyclohexanedimethanolwere prepared as described below, having the composition and propertiesshown on Table 3. The balance up to 100 mol % of the diol component ofthe polyesters in Table 3 was 1,4-cyclohexanedimethanol (31/69cis/trans).

Materials were injection molded into both 3.2 mm and 6.4 mm thick barsand subsequently notched for Izod impact testing. The notched Izodimpact strengths were obtained at 23° C. and are reported in Table 3.Density, Tg, and crystallization halftime were measured on the moldedbars. Melt viscosity was measured on pellets at 290° C.

TABLE 3 Compilation of various properties for certain polyesters usefulin the invention Notched Notched Izod of Izod of 3.2 mm 6.4 mm Meltthick thick Crystallization Viscosity Pellet Molded bars at bars atSpecific Halftime from at 1 rad/sec TMCD % cis IV Bar IV 23° C. 23° C.Gravity Tg melt at 170° C. at 290° C. Example mole % TMCD (dl/g) (dl/g)(J/m) (J/m) (g/mL) (° C.) (min) (Poise) A 15 48.8 0.736 0.707 1069 8781.184 104 15 5649 B 18 NA 0.728 0.715 980 1039 1.183 108 22 6621 C 20 NA0.706 0.696 1006 1130 1.182 106 52 6321 D 22 NA 0.732 0.703 959 9881.178 108 63 7161 E 21 NA 0.715 0.692 932 482 1.179 110 56 6162 F 24 NA0.708 0.677 976 812 1.180 109 58 6282 G 23 NA 0.650 0.610 647 270 1.182107 46 3172 H 23 47.9 0.590 0.549 769 274 1.181 106 47 1736 I 23 48.10.531 0.516 696 352 1.182 105 19 1292 J 23 47.8 0.364 NA NA NA NA 98 NA167 NA = Not available.

Example 3A

21.24 lb (49.71 gram-mol) dimethyl terephthalate, 14.34 lb (45.21gram-mol) 1,4-cyclohexanedimethanol, and 4.58 lb (14.44 gram-mol)2,2,4,4-tetramethyl-1,3-cyclobutanediol were reacted together in thepresence of 200 ppm of the catalyst butyltin tris(2-ethylhexanoate). Thereaction was carried out under a nitrogen gas purge in an 18-gallonstainless steel pressure vessel fitted with a condensing column, avacuum system, and a HELICONE-type agitator. With the agitator runningat 25 RPM, the reaction mixture temperature was increased to 250° C. andthe pressure was increased to 20 psig. The reaction mixture was held for2 hours at 250° C. and at a pressure of 20 psig. The pressure was thendecreased to 0 psig at a rate of 3 psig/minute. The temperature of thereaction mixture was then increased to 270° C. and the pressure wasdecreased to 90 mm of Hg. After a 1 hour hold time at 270° C. and 90 mmof Hg, the agitator speed was decreased to 15 RPM, the reaction mixturetemperature was increased to 290° C., and the pressure was decreased to<1 mm of Hg. The reaction mixture was held at 290° C. and at a pressureof <1 mm of Hg until the power draw to the agitator no longer increased(70 minutes). The pressure of the pressure vessel was then increased to1 atmosphere using nitrogen gas. The molten polymer was then extrudedfrom the pressure vessel. The cooled, extruded polymer was ground topass a 6-mm screen. The polymer had an inherent viscosity of 0.736 dL/gand a Tg of 104° C. NMR analysis showed that the polymer was composed of85.4 mol % 1,4-cyclohexane-dimethanol residues and 14.6 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues. The polymer had colorvalues of: L*=78.20, a*=−1.62, and b*=6.23.

Example 3B to Example 3D

The polyesters described in Example 3B to Example 3D were preparedfollowing a procedure similar to the one described for Example 3A. Thecomposition and properties of these polyesters are shown in Table 3.

Example 3E

21.24 lb (49.71 gram-mol) dimethyl terephthalate, 12.61 lb (39.77gram-mol) 1,4-cyclohexanedimethanol, and 6.30 lb (19.88 gram-mol)2,2,4,4-tetramethyl-1,3-cyclobutanediol were reacted together in thepresence of 200 ppm of the catalyst butyltin tris(2-ethylhexanoate). Thereaction was carried out under a nitrogen gas purge in an 18-gallonstainless steel pressure vessel fitted with a condensing column, avacuum system, and a HELICONE-type agitator. With the agitator runningat 25 RPM, the reaction mixture temperature was increased to 250° C. andthe pressure was increased to 20 psig. The reaction mixture was held for2 hours at 250° C. and 20 psig pressure. The pressure was then decreasedto 0 psig at a rate of 3 psig/minute. The temperature of the reactionmixture was then increased to 270° C. and the pressure was decreased to90 mm of Hg. After a 1 hour hold time at 270° C. and 90 mm of Hg, theagitator speed was decreased to 15 RPM, the reaction mixture temperaturewas increased to 290° C., and the pressure was decreased to <1 mm of Hg.The reaction mixture was held at 290° C. and at a pressure of <1 mm ofHg for 60 minutes. The pressure of the pressure vessel was thenincreased to 1 atmosphere using nitrogen gas. The molten polymer wasthen extruded from the pressure vessel. The cooled, extruded polymer wasground to pass a 6-mm screen. The polymer had an inherent viscosity of0.715 dL/g and a Tg of 110° C. X-ray analysis showed that the polyesterhad 223 ppm tin. NMR analysis showed that the polymer was composed of78.6 mol % 1,4-cyclohexane-dimethanol residues and 21.4 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues. The polymer had colorvalues of: L*=76.45, a*=−1.65, and b*=6.47.

Example 3F

The polyester described in Example 3F was prepared following a proceduresimilar to the one described for Example 3A. The composition andproperties of this polyester are shown in Table 3.

Example 3H

21.24 lb (49.71 gram-mol) dimethyl terephthalate, 12.61 lb (39.77gram-mol) 1,4-cyclohexanedimethanol, and 6.30 lb (19.88 gram-mol)2,2,4,4-tetramethyl-1,3-cyclobutanediol were reacted together in thepresence of 200 ppm of the catalyst butyltin tris(2-ethylhexanoate). Thereaction was carried out under a nitrogen gas purge in an 18-gallonstainless steel pressure vessel fitted with a condensing column, avacuum system, and a HELICONE-type agitator. With the agitator runningat 25 RPM, the reaction mixture temperature was increased to 250° C. andthe pressure was increased to 20 psig. The reaction mixture was held for2 hours at 250° C. and 20 psig pressure. The pressure was then decreasedto 0 psig at a rate of 3 psig/minute. The temperature of the reactionmixture was then increased to 270° C. and the pressure was decreased to90 mm of Hg. After a 1 hour hold time at 270° C. and 90 mm of Hg, theagitator speed was decreased to 15 RPM, the reaction mixture temperaturewas increased to 290° C., and the pressure was decreased to <1 mm of Hg.The reaction mixture was held at 290° C. and at a pressure of <1 mm ofHg for 12 minutes. The pressure of the pressure vessel was thenincreased to 1 atmosphere using nitrogen gas. The molten polymer wasthen extruded from the pressure vessel. The cooled, extruded polymer wasground to pass a 6-mm screen. The polymer had an inherent viscosity of0.590 dL/g and a Tg of 106° C. NMR analysis showed that the polymer wascomposed of 77.1 mol % 1,4-cyclohexane-dimethanol residues and 22.9 mol% 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues. The polymer hadcolor values of: L*=83.27, a*=−1.34, and b*=5.08.

Example 3I

21.24 lb (49.71 gram-mol) dimethyl terephthalate, 12.61 lb (39.77gram-mol) 1,4-cyclohexanedimethanol, and 6.30 lb (19.88 gram-mol)2,2,4,4-tetramethyl-1,3-cyclobutanediol were reacted together in thepresence of 200 ppm of the catalyst butyltin tris(2-ethylhexanoate). Thereaction was carried out under a nitrogen gas purge in an 18-gallonstainless steel pressure vessel fitted with a condensing column, avacuum system, and a HELICONE-type agitator. With the agitator runningat 25 RPM, the reaction mixture temperature was increased to 250° C. andthe pressure was increased to 20 psig. The reaction mixture was held for2 hours at 250° C. and 20 psig pressure. The pressure was then decreasedto 0 psig at a rate of 3 psig/minute. The temperature of the reactionmixture was then increased to 270° C. and the pressure was decreased to90 mm of Hg. After a 1 hour hold time at 270° C. and 90 mm of Hg, theagitator speed was decreased to 15 RPM, the reaction mixture temperaturewas increased to 290° C., and the pressure was decreased to 4 mm of Hg.The reaction mixture was held at 290° C. and at a pressure of 4 mm of Hgfor 30 minutes. The pressure of the pressure vessel was then increasedto 1 atmosphere using nitrogen gas. The molten polymer was then extrudedfrom the pressure vessel. The cooled, extruded polymer was ground topass a 6-mm screen. The polymer had an inherent viscosity of 0.531 dL/gand a Tg of 105° C. NMR analysis showed that the polymer was composed of76.9 mol % 1,4-cyclohexane-dimethanol residues and 23.1 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues. The polymer had colorvalues of: L*=80.42, a*=−1.28, and b*=5.13.

Example 3J

21.24 lb (49.71 gram-mol) dimethyl terephthalate, 12.61 lb (39.77gram-mol) 1,4-cyclohexanedimethanol, and 6.30 lb (19.88 gram-mol)2,2,4,4-tetramethyl-1,3-cyclobutanediol were reacted together in thepresence of 200 ppm of the catalyst butyltin tris(2-ethylhexanoate). Thereaction was carried out under a nitrogen gas purge in an 18-gallonstainless steel pressure vessel fitted with a condensing column, avacuum system, and a HELICONE-type agitator. With the agitator runningat 25 RPM, the reaction mixture temperature was increased to 250° C. andthe pressure was increased to 20 psig. The reaction mixture was held for2 hours at 250° C. and 20 psig pressure. The pressure was then decreasedto 0 psig at a rate of 3 psig/minute. The temperature of the reactionmixture was then increased to 270° C. and the pressure was decreased to90 mm of Hg. After a 1 hour hold time at 270° C. and 90 mm of Hg, theagitator speed was decreased to 15 RPM, the reaction mixture temperaturewas increased to 290° C., and the pressure was decreased to 4 mm of Hg.When the reaction mixture temperature was 290° C. and the pressure was 4mm of Hg, the pressure of the pressure vessel was immediately increasedto 1 atmosphere using nitrogen gas. The molten polymer was then extrudedfrom the pressure vessel. The cooled, extruded polymer was ground topass a 6-mm screen. The polymer had an inherent viscosity of 0.364 dL/gand a Tg of 98° C. NMR analysis showed that the polymer was composed of77.5 mol % 1,4-cyclohexane-dimethanol residues and 22.5 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues. The polymer had colorvalues of: L*=77.20, a*=−1.47, and b*=4.62.

Example 4 Comparative Example

This example shows data for comparative materials in Table 4. The PC wasMakrolon 2608 from Bayer, with a nominal composition of 100 mole %bisphenol A residues and 100 mole % diphenyl carbonate residues.Makrolon 2608 has a nominal melt flow rate of 20 grams/10 minutesmeasured at 300 C using a 1.2 kg weight. The PET was Eastar 9921 fromEastman Chemical Company, with a nominal composition of 100 mole %terephthalic acid, 3.5 mole % cyclohexanedimethanol (CHDM) and 96.5 mole% ethylene glycol. The PETG was Eastar 6763 from Eastman ChemicalCompany, with a nominal composition of 100 mole % terephthalic acid, 31mole % cyclohexanedimethanol (CHDM) and 69 mole % ethylene glycol. ThePCTG was Eastar DN001 from Eastman Chemical Company, with a nominalcomposition of 100 mole % terephthalic acid, 62 mole %cyclohexanedimethanol (CHDM) and 38 mole % ethylene glycol. The PCTA wasEastar AN001 from Eastman Chemical Company, with a nominal compositionof 65 mole % terephthalic acid, 35 mole % isophthalic acid and 100 mole% cyclohexanedimethanol (CHDM). The Polysulfone was Udel 1700 fromSolvay, with a nominal composition of 100 mole % bisphenol A residuesand 100 mole % 4,4-dichlorosulfonyl sulfone residues. Udel 1700 has anominal melt flow rate of 6.5 grams/10 minutes measured at 343 C using a2.16 kg weight. The SAN was Lustran 31 from Lanxess, with a nominalcomposition of 76 weight % styrene and 24 weight % acrylonitrile.Lustran 31 has a nominal melt flow rate of 7.5 grams/10 minutes measuredat 230 C using a 3.8 kg weight. The examples of the invention showimproved toughness in 6.4 mm thickness bars compared to all of the otherresins.

TABLE 4 Compilation of various properties for certain commercialpolymers Notched Notched Izod of Izod of 3.2 mm 6.4 mm thick thickCrystallization Pellet Molded bars at bars at Specific Halftime fromPolymer IV Bar IV 23° C. 23° C. Gravity Tg melt Example name (dl/g)(dl/g) (J/m) (J/m) (g/mL) (° C.) (min) A PC   12 MFR NA 929  108 1.20146 NA B PCTG 0.73 0.696 NB 70 1.23 87 30 at 170° C. C PCTA 0.72 0.70298 59 1.20 87 15 at 150° C. D PETG 0.75 0.692 83 59 1.27 80 2500 at 130°C.  E PET 0.76 0.726 45 48 1.33 78 1.5 at 170° C.  F SAN  7.5 MFR NA 21NA 1.07 ~110 NA G PSU  6.5 MFR NA 69 NA 1.24 ~190 NA NA = Not available

Example 5

This example illustrates the effect of the amount of2,2,4,4-tetramethyl-1,3-cyclobutanediol used for the preparation of thepolyesters of the invention on the glass transition temperature of thepolyesters. Polyesters prepared in this example comprise from 15 to 25mol % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.

Example 5A to Example 5G

Dimethyl terephthalate, 1,4-cyclohexanedimethanol, and2,2,4,4-tetramethyl-1,3-cyclobutanediol were weighed into a 500-mlsingle neck round bottom flask. NMR analysis on the2,2,4,4-tetramethyl-1,3-cyclobutanediol starting material showed acis/trans ratio of 53/47. The polyesters of this example were preparedwith a 1.2/1 glycol/acid ratio with the entire excess coming from the2,2,4,4-tetramethyl-1,3-cyclobutanediol. Enough dibutyltin oxidecatalyst was added to give 300 ppm tin in the final polymer. The flaskwas under a 0.2 SCFC nitrogen purge with vacuum reduction capability.The flask was immersed in a Belmont metal bath at 200° C. and stirred at200 RPM after the reactants had melted. After about 2.5 hours, thetemperature was raised to 210° C. and these conditions were held for anadditional 2 hours. The temperature was raised to 285° C. (inapproximately 25 minutes) and the pressure was reduced to 0.3 mm of Hgover a period of 5 minutes. The stirring was reduced as the viscosityincreased, with 15 RPM being the minimum stirring used. The totalpolymerization time was varied to attain the target inherentviscosities. After the polymerization was complete, the Belmont metalbath was lowered and the polymer was allowed to cool to below its glasstransition temperature. After about 30 minutes, the flask was reimmersedin the Belmont metal bath (the temperature had been increased to 295° C.during this 30 minute wait) and the polymer mass was heated until itpulled away from the glass flask. The polymer mass was stirred at midlevel in the flask until the polymer had cooled. The polymer was removedfrom the flask and ground to pass a 3 mm screen. Variations to thisprocedure were made to produce the copolyesters described below with atargeted composition of 20 mol %.

Inherent viscosities were measured as described in the “MeasurementMethods” section above. The compositions of the polyesters weredetermined by ¹H NMR as explained before in the Measurement Methodssection. The glass transition temperatures were determined by DSC, usingthe second heat after quench at a rate of 20° C./min.

Example 5H to Example 5Q

These polyesters were prepared by carrying out the ester exchange andpolycondensation reactions in separate stages. The ester exchangeexperiments were conducted in a continuous temperature rise (CTR)reactor. The CTR was a 3000 ml glass reactor equipped with a singleshaft impeller blade agitator, covered with an electric heating mantleand fitted with a heated packed reflux condenser column. The reactor wascharged with 777 g (4 moles) of dimethyl terephthalate, 230 g (1.6moles) of 2,2,4,4-tetramethyl-1,3,-cyclobutanediol, 460.8 g (3.2 moles)of cyclohexane dimethanol and 1.12 g of butyltin tris-2-ethylhexanoate(such that there will be 200 ppm tin metal in the final polymer). Theheating mantle was set manually to 100% output. The set points and datacollection were facilitated by a Camile process control system. Once thereactants were melted, stirring was initiated and slowly increased to250 rpm. The temperature of the reactor gradually increased with runtime. The weight of methanol collected was recorded via balance. Thereaction was stopped when methanol evolution stopped or at apre-selected lower temperature of 260°. The oligomer was discharged witha nitrogen purge and cooled to room temperature. The oligomer was frozenwith liquid nitrogen and broken into pieces small enough to be weighedinto a 500 ml round bottom flask.

In the polycondensation reactions, a 500 ml round bottom flask wascharged with approximately 150 g of the oligomer prepared above. Theflask was equipped with a stainless steel stirrer and polymer head. Theglassware was set up on a half mole polymer rig and the Camile sequencewas initiated. The stirrer was positioned one full turn from the flaskbottom once the oligomer melted. The temperature/pressure/stir ratesequence controlled by the Camile software for each example is reportedin the following tables.

Camile Sequence for Example 5H and Example 5I

Time Temp Vacuum Stir Stage (min) (° C.) (torr) (rpm) 1 5 245 760 0 2 5245 760 50 3 30 265 760 50 4 3 265 90 50 5 110 290 90 50 6 5 290 6 25 7110 290 6 25

Camile Sequence for Example 5N to Example 5Q

Time Temp Vacuum Stir Stage (min) (° C.) (torr) (rpm) 1 5 245 760 0 2 5245 760 50 3 30 265 760 50 4 3 265 90 50 5 110 290 90 50 6 5 290 3 25 7110 290 3 25

Camile Sequence for Example 5K and Example 5L

Time Temp Vacuum Stir Stage (min) (° C.) (torr) (rpm) 1 5 245 760 0 2 5245 760 50 3 30 265 760 50 4 3 265 90 50 5 110 290 90 50 6 5 290 2 25 7110 290 2 25

Camile Sequence for Example 5J and Example 5M

Time Temp Vacuum Stir Stage (min) (° C.) (torr) (rpm) 1 5 245 760 0 2 5245 760 50 3 30 265 760 50 4 3 265 90 50 5 110 290 90 50 6 5 290 1 25 7110 290 1 25

The resulting polymers were recovered from the flask, chopped using ahydraulic chopper, and ground to a 6 mm screen size. Samples of eachground polymer were submitted for inherent viscosity in 60/40 (wt/wt)phenol/tetrachloroethane at a concentration of 0.5 g/100 ml at 25° C.,catalyst level (Sn) by x-ray fluorescence, and color (L*, a*, b*) bytransmission spectroscopy. Polymer composition was obtained by ¹H NMR.Samples were submitted for thermal stability and melt viscosity testingusing a Rheometrics Mechanical Spectrometer (RMS-800).

The table below shows the experimental data for the polyesters of thisexample. The data shows that an increase in the level of2,2,4,4-tetramethyl-1,3-cyclobutanediol raises the glass transitiontemperature in an almost linear fashion, for a constant inherentviscosity. FIG. 3 also shows the dependence of Tg on composition andinherent viscosity.

TABLE 5 Glass transition temperature as a function of inherent viscosityand composition η_(o) at η_(o) at η_(o) at Exam- mol % % cis IV T_(g)260° C. 275° C. 290° C. ple TMCD TMCD (dL/g) (° C.) (Poise) (Poise)(Poise) A 20 51.4 0.72 109 11356 19503 5527 B 19.1 51.4 0.60 106 68913937 2051 C 19 53.2 0.64 107 8072 4745 2686 D 18.8 54.4 0.70 108 149378774 4610 E 17.8 52.4 0.50 103 3563 1225 883 F 17.5 51.9 0.75 107 2116010877 5256 G 17.5 52 0.42 98 NA NA NA H 22.8 53.5 0.69 109 NA NA NA I22.7 52.2 0.68 108 NA NA NA J 23.4 52.4 0.73 111 NA NA NA K 23.3 52.90.71 111 NA NA NA L 23.3 52.4 0.74 112 NA NA NA M 23.2 52.5 0.74 112 NANA NA N 23.1 52.5 0.71 111 NA NA NA O 22.8 52.4 0.73 112 NA NA NA P 22.753 0.69 112 NA NA NA Q 22.7 52 0.70 111 NA NA NA NA = Not available

Example 6 Comparative Example

This example illustrates that a polyester based on 100%2,2,4,4-tetramethyl-1,3-cyclobutanediol has a slow crystallizationhalf-time.

A polyester based solely on terephthalic acid and2,2,4,4-tetramethyl-1,3-cyclobutanediol was prepared in a method similarto the method described in Example 1A with the properties shown on Table6. This polyester was made with 300 ppm dibutyl tin oxide. The trans/cisratio of the 2,2,4,4-tetramethyl-1,3-cyclobutanediol was 65/35.

Films were pressed from the ground polymer at 320° C. Crystallizationhalf-time measurements from the melt were made at temperatures from 220to 250° C. at 10° C. increments and are reported in Table 6. The fastestcrystallization half-time for the sample was taken as the minimum valueof crystallization half-time as a function of temperature. The fastestcrystallization half-time of this polyester is around 1300 minutes. Thisvalue contrasts with the fact that the polyester (PCT) based solely onterephthalic acid and 1,4-cyclohexanedimethanol (no comonomermodification) has an extremely short crystallization half-time (<1 min)as shown in FIG. 1.

TABLE 6 Crystallization Half-times (min) at at at at Comonomer IV T_(g)T_(max) 220° C. 230° C. 240° C. 250° C. (mol %) (dl/g) (° C.) (° C.)(min) (min) (min) (min) 100 mol % F 0.63 170.0 330 3291 3066 1303 1888where: F is 2,2,4,4-Tetramethyl-1,3-cyclobutanediol (65/35 Trans/Cis)

Example 7

Sheets comprising a polyester that had been prepared with a targetcomposition of 100 mole % terephthalic acid residues, 80 mole %1,4-cyclohexanedimethanol residues, and 20 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues were produced using a3.5 inch single screw extruder. A sheet was extruded continuously,gauged to a thickness of 177 mil and then various sheets were sheared tosize. Inherent viscosity and glass transition temperature were measuredon one sheet. The sheet inherent viscosity was measured to be 0.69 dl/g.The glass transition temperature of the sheet was measured to be 106° C.Sheets were then conditioned at 50% relative humidity and 60° C. for 2weeks. Sheets were subsequently thermoformed into a female mold having adraw ratio of 2.5:1 using a Brown thermoforming machine. Thethermoforming oven heaters were set to 70/60/60% output using top heatonly. Sheets were left in the oven for various amounts of time in orderto determine the effect of sheet temperature on the part quality asshown in the table below. Part quality was determined by measuring thevolume of the thermoformed part, calculating the draw, and visuallyinspecting the thermoformed part. The draw was calculated as the partvolume divided by the maximum part volume achieved in this set ofexperiments (Example G). The thermoformed part was visually inspectedfor any blisters and the degree of blistering rated as none (N), low(L), or high (H). The results below demonstrate that these thermoplasticsheets with a glass transition temperature of 106° C. can bethermoformed under the conditions shown below, as evidenced by thesesheets having at least 95% draw and no blistering, without predrying thesheets prior to thermoforming.

Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 86 145 50164 N B 100 150 500 63 N C 118 156 672 85 N D 135 163 736 94 N E 143 166760 97 N F 150 168 740 94 L G 159 172 787 100 L

Example 8

Sheets comprising a polyester that had been prepared with a targetcomposition of 100 mole % terephthalic acid residues, 80 mole %1,4-cyclohexanedimethanol residues, and 20 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues were produced using a3.5 inch single screw. A sheet was extruded continuously, gauged to athickness of 177 mil and then various sheets were sheared to size.Inherent viscosity and glass transition temperature were measured on onesheet. The sheet inherent viscosity was measured to be 0.69 dl/g. Theglass transition temperature of the sheet was measured to be 106° C.Sheets were then conditioned at 100% relative humidity and 25° C. for 2weeks. Sheets were subsequently thermoformed into a female mold having adraw ratio of 2.5:1 using a Brown thermoforming machine. Thethermoforming oven heaters were set to 60/40/40% output using top heatonly. Sheets were left in the oven for various amounts of time in orderto determine the effect of sheet temperature on the part quality asshown in the table below. Part quality was determined by measuring thevolume of the thermoformed part, calculating the draw, and visuallyinspecting the thermoformed part. The draw was calculated as the partvolume divided by the maximum part volume achieved in this set ofexperiments (Example G). The thermoformed part was visually inspectedfor any blisters and the degree of blistering rated as none (N), low(L), or high (H). The results below demonstrate that these thermoplasticsheets with a glass transition temperature of 106° C. can bethermoformed under the conditions shown below, as evidenced by theproduction of sheets having at least 95% draw and no blistering, withoutpredrying the sheets prior to thermoforming.

Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 141 154 39453 N B 163 157 606 82 N C 185 160 702 95 N D 195 161 698 95 N E 215 163699 95 L F 230 168 705 96 L G 274 174 737 100 H H 275 181 726 99 H

Example 9 Comparative Example

Sheets consisting of Kelvx 201 were produced using a 3.5 inch singlescrew extruder. Kelvx is a blend consisting of 69.85% PCTG (Eastar fromEastman Chemical Co. having 100 mole % terephthalic acid residues, 62mole % 1,4-cyclohexanedimethanol residues, and 38 mole % ethylene glycolresidues); 30% PC (bisphenol A polycarbonate); and 0.15% Weston 619(stabilizer sold by Crompton Corporation). A sheet was extrudedcontinuously, gauged to a thickness of 177 mil and then various sheetswere sheared to size. The glass transition temperature was measured onone sheet and was 100° C. Sheets were then conditioned at 50% relativehumidity and 60° C. for 2 weeks. Sheets were subsequently thermoformedinto a female mold having a draw ratio of 2.5:1 using a Brownthermoforming machine. The thermoforming oven heaters were set to70/60/60% output using top heat only. Sheets were left in the oven forvarious amounts of time in order to determine the effect of sheettemperature on the part quality as shown in the table below. Partquality was determined by measuring the volume of the thermoformed part,calculating the draw, and visually inspecting the thermoformed part. Thedraw was calculated as the part volume divided by the maximum partvolume achieved in this set of experiments (Example E). The thermoformedpart was visually inspected for any blisters and the degree ofblistering rated as none (N), low (L), or high (H). The results belowdemonstrate that these thermoplastic sheets with a glass transitiontemperature of 100° C. can be thermoformed under the conditions shownbelow, as evidenced by the production of sheets having at least 95% drawand no blistering, without predrying the sheets prior to thermoforming.

Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 90 146 58275 N B 101 150 644 83 N C 111 154 763 98 N D 126 159 733 95 N E 126 159775 100 N F 141 165 757 98 N G 148 168 760 98 L

Example 10 Comparative Example

Sheets consisting of Kelvx 201 were produced using a 3.5 inch singlescrew extruder. A sheet was extruded continuously, gauged to a thicknessof 177 mil and then various sheets were sheared to size. The glasstransition temperature was measured on one sheet and was 100° C. Sheetswere then conditioned at 100% relative humidity and 25° C. for 2 weeks.Sheets were subsequently thermoformed into a female mold having a drawratio of 2.5:1 using a Brown thermoforming machine. The thermoformingoven heaters were set to 60/40/40% output using top heat only. Sheetswere left in the oven for various amounts of time in order to determinethe effect of sheet temperature on the part quality as shown in thetable below. Part quality was determined by measuring the volume of thethermoformed part, calculating the draw, and visually inspecting thethermoformed part. The draw was calculated as the part volume divided bythe maximum part volume achieved in this set of experiments (Example H).The thermoformed part was visually inspected for any blisters and thedegree of blistering rated as none (N), low (L), or high (H). Theresults below demonstrate that these thermoplastic sheets with a glasstransition temperature of 100° C. can be thermoformed under theconditions shown below, as evidenced by the production of sheets havinggreater than 95% draw and no blistering, without predrying the sheetsprior to thermoforming.

Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 110 143 18525 N B 145 149 529 70 N C 170 154 721 95 N D 175 156 725 96 N E 185 157728 96 N F 206 160 743 98 L G 253 NR 742 98 H H 261 166 756 100 H NR =Not recorded

Example 11 Comparative Example

Sheets consisting of PCTG 25976 (100 mole % terephthalic acid residues,62 mole % 1,4-cyclohexanedimethanol residues, and 38 mole % ethyleneglycol residues) were produced using a 3.5 inch single screw extruder. Asheet was extruded continuously, gauged to a thickness of 118 mil andthen various sheets were sheared to size. The glass transitiontemperature was measured on one sheet and was 87° C. Sheets were thenconditioned at 50% relative humidity and 60° C. for 4 weeks. Themoisture level was measured to be 0.17 wt %. Sheets were subsequentlythermoformed into a female mold having a draw ratio of 2.5:1 using aBrown thermoforming machine. The thermoforming oven heaters were set to70/60/60% output using top heat only. Sheets were left in the oven forvarious amounts of time in order to determine the effect of sheettemperature on the part quality as shown in the table below. Partquality was determined by measuring the volume of the thermoformed part,calculating the draw, and visually inspecting the thermoformed part. Thedraw was calculated as the part volume divided by the maximum partvolume achieved in this set of experiments (Example A). The thermoformedpart was visually inspected for any blisters and the degree ofblistering rated as none (N), low (L), or high (H). The results belowdemonstrate that these thermoplastic sheets with a glass transitiontemperature of 87° C. can be thermoformed under the conditions shownbelow, as evidenced by the production of sheets having greater than 95%draw and no blistering, without predrying the sheets prior tothermoforming.

Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 102 183 816100 N B 92 171 811 99 N C 77 160 805 99 N D 68 149 804 99 N E 55 143 79097 N F 57 138 697 85 N

Example 12 Comparative Example

A miscible blend consisting of 20 wt % Teijin L-1250 polycarbonate (abisphenol-A polycarbonate), 79.85 wt % PCTG 25976, and 0.15 wt % Weston619 was produced using a 1.25 inch single screw extruder. Sheetsconsisting of the blend were then produced using a 3.5 inch single screwextruder. A sheet was extruded continuously, gauged to a thickness of118 mil and then various sheets were sheared to size. The glasstransition temperature was measured on one sheet and was 94° C. Sheetswere then conditioned at 50% relative humidity and 60° C. for 4 weeks.The moisture level was measured to be 0.25 wt %. Sheets weresubsequently thermoformed into a female mold having a draw ratio of2.5:1 using a Brown thermoforming machine. The thermoforming ovenheaters were set to 70/60/60% output using top heat only. Sheets wereleft in the oven for various amounts of time in order to determine theeffect of sheet temperature on the part quality as shown in the tablebelow. Part quality was determined by measuring the volume of thethermoformed part, calculating the draw, and visually inspecting thethermoformed part. The draw was calculated as the part volume divided bythe maximum part volume achieved in this set of experiments (Example A).The thermoformed part was visually inspected for any blisters and thedegree of blistering rated as none (N), low (L), or high (H). Theresults below demonstrate that these thermoplastic sheets with a glasstransition temperature of 94° C. can be thermoformed under theconditions shown below, as evidenced by the production of sheets havinggreater than 95% draw and no blistering, without predrying the sheetsprior to thermoforming.

Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 92 184 844100 H B 86 171 838 99 N C 73 160 834 99 N D 58 143 787 93 N E 55 143 66579 N

Example 13 Comparative Example

A miscible blend consisting of 30 wt % Teijin L-1250 polycarbonate,69.85 wt % PCTG 25976, and 0.15 wt % Weston 619 was produced using a1.25 inch single screw extruder. Sheets consisting of the blend werethen produced using a 3.5 inch single screw extruder. A sheet wasextruded continuously, gauged to a thickness of 118 mil and then varioussheets were sheared to size. The glass transition temperature wasmeasured on one sheet and was 99° C. Sheets were then conditioned at 50%relative humidity and 60° C. for 4 weeks. The moisture level wasmeasured to be 0.25 wt %. Sheets were subsequently thermoformed into afemale mold having a draw ratio of 2.5:1 using a Brown thermoformingmachine. The thermoforming oven heaters were set to 70/60/60% outputusing top heat only. Sheets were left in the oven for various amounts oftime in order to determine the effect of sheet temperature on the partquality as shown in the table below. Part quality was determined bymeasuring the volume of the thermoformed part, calculating the draw, andvisually inspecting the thermoformed part. The draw was calculated asthe part volume divided by the maximum part volume achieved in this setof experiments (Example A). The thermoformed part was visually inspectedfor any blisters and the degree of blistering rated as none (N), low(L), or high (H). The results below demonstrate that these thermoplasticsheets with a glass transition temperature of 99° C. can be thermoformedunder the conditions shown below, as evidenced by the production ofsheets having greater than 95% draw and no blistering, without predryingthe sheets prior to thermoforming.

Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 128 194 854100 H B 98 182 831 97 L C 79 160 821 96 N D 71 149 819 96 N E 55 145 78592 N F 46 143 0 0 NA G 36 132 0 0 NA NA = not applicable. A value ofzero indicates that the sheet was not formed because it did not pullinto the mold (likely because it was too cold).

Example 14 Comparative Example

A miscible blend consisting of 40 wt % Teijin L-1250 polycarbonate,59.85 wt % PCTG 25976, and 0.15 wt % Weston 619 was produced using a1.25 inch single screw extruder. Sheets consisting of the blend werethen produced using a 3.5 inch single screw extruder. A sheet wasextruded continuously, gauged to a thickness of 118 mil and then varioussheets were sheared to size. The glass transition temperature wasmeasured on one sheet and was 105° C. Sheets were then conditioned at50% relative humidity and 60° C. for 4 weeks. The moisture level wasmeasured to be 0.265 wt %. Sheets were subsequently thermoformed into afemale mold having a draw ratio of 2.5:1 using a Brown thermoformingmachine. The thermoforming oven heaters were set to 70/60/60% outputusing top heat only. Sheets were left in the oven for various amounts oftime in order to determine the effect of sheet temperature on the partquality as shown in the table below. Part quality was determined bymeasuring the volume of the thermoformed part, calculating the draw, andvisually inspecting the thermoformed part. The draw was calculated asthe part volume divided by the maximum part volume achieved in this setof experiments (Examples 8A to 8E). The thermoformed part was visuallyinspected for any blisters and the degree of blistering rated as none(N), low (L), or high (H). The results below demonstrate that thesethermoplastic sheets with a glass transition temperature of 105° C. canbe thermoformed under the conditions shown below, as evidenced by theproduction of sheets having greater than 95% draw and no blistering,without predrying the sheets prior to thermoforming.

Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 111 191 828100 H B 104 182 828 100 H C 99 179 827 100 N D 97 177 827 100 N E 78 160826 100 N F 68 149 759 92 N G 65 143 606 73 N

Example 15 Comparative Example

A miscible blend consisting of 50 wt % Teijin L-1250 polycarbonate,49.85 wt % PCTG 25976, and 0.15 wt % Weston 619 was produced using a1.25 inch single screw extruder. A sheet was extruded continuously,gauged to a thickness of 118 mil and then various sheets were sheared tosize. The glass transition temperature was measured on one sheet and was1111C. Sheets were then conditioned at 50% relative humidity and 60° C.for 4 weeks. The moisture level was measured to be 0.225 wt %. Sheetswere subsequently thermoformed into a female mold having a draw ratio of2.5:1 using a Brown thermoforming machine. The thermoforming ovenheaters were set to 70/60/60% output using top heat only. Sheets wereleft in the oven for various amounts of time in order to determine theeffect of sheet temperature on the part quality as shown in the tablebelow. Part quality was determined by measuring the volume of thethermoformed part, calculating the draw, and visually inspecting thethermoformed part. The draw was calculated as the part volume divided bythe maximum part volume achieved in this set of experiments (Examples Ato D). The thermoformed part was visually inspected for any blisters andthe degree of blistering rated as none (N), low (L), or high (H). Theresults below demonstrate that these thermoplastic sheets with a glasstransition temperature of 111° C. can be thermoformed under theconditions shown below, as evidenced by the production of sheets havinggreater than 95% draw and no blistering, without predrying the sheetsprior to thermoforming.

Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 118 192 815100 H B 99 182 815 100 H C 97 177 814 100 L D 87 171 813 100 N E 80 160802 98 N F 64 154 739 91 N G 60 149 0 0 NA NA = not applicable. A valueof zero indicates that the sheet was not formed because it did not pullinto the mold (likely because it was too cold).

Example 16 Comparative Example

A miscible blend consisting of 60 wt % Teijin L-1250 polycarbonate,39.85 wt % PCTG 25976, and 0.15 wt % Weston 619 was produced using a1.25 inch single screw extruder. Sheets consisting of the blend werethen produced using a 3.5 inch single screw extruder. A sheet wasextruded continuously, gauged to a thickness of 118 mil and then varioussheets were sheared to size. The glass transition temperature wasmeasured on one sheet and was 117° C. Sheets were then conditioned at50% relative humidity and 60° C. for 4 weeks. The moisture level wasmeasured to be 0.215 wt %. Sheets were subsequently thermoformed into afemale mold having a draw ratio of 2.5:1 using a Brown thermoformingmachine. The thermoforming oven heaters were set to 70/60/60% outputusing top heat only. Sheets were left in the oven for various amounts oftime in order to determine the effect of sheet temperature on the partquality as shown in the table below. Part quality was determined bymeasuring the volume of the thermoformed part, calculating the draw, andvisually inspecting the thermoformed part. The draw was calculated asthe part volume divided by the maximum part volume achieved in this setof experiments (Example A). The thermoformed part was visually inspectedfor any blisters and the degree of blistering rated as none (N), low(L), or high (H). The results below demonstrate that these thermoplasticsheets with a glass transition temperature of 117° C. cannot bethermoformed under the conditions shown below, as evidenced by theinability to produce sheets having greater than 95% draw and noblistering, without predrying the sheets prior to thermoforming.

Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 114 196 813100 H B 100 182 804 99 H C 99 177 801 98 L D 92 171 784 96 L E 82 168727 89 L F 87 166 597 73 N

Example 17 Comparative Example

A miscible blend consisting of 65 wt % Teijin L-1250 polycarbonate,34.85 wt % PCTG 25976, and 0.15 wt % Weston 619 was produced using a1.25 inch single screw extruder. Sheets consisting of the blend werethen produced using a 3.5 inch single screw extruder. A sheet wasextruded continuously, gauged to a thickness of 118 mil and then varioussheets were sheared to size. The glass transition temperature wasmeasured on one sheet and was 120° C. Sheets were then conditioned at50% relative humidity and 60° C. for 4 weeks. The moisture level wasmeasured to be 0.23 wt %. Sheets were subsequently thermoformed into afemale mold having a draw ratio of 2.5:1 using a Brown thermoformingmachine. The thermoforming oven heaters were set to 70/60/60% outputusing top heat only. Sheets were left in the oven for various amounts oftime in order to determine the effect of sheet temperature on the partquality as shown in the table below. Part quality was determined bymeasuring the volume of the thermoformed part, calculating the draw, andvisually inspecting the thermoformed part. The draw was calculated asthe part volume divided by the maximum part volume achieved in this setof experiments (Example A). The thermoformed part was visually inspectedfor any blisters and the degree of blistering rated as none (N), low(L), or high (H). The results below demonstrate that these thermoplasticsheets with a glass transition temperature of 120° C. cannot bethermoformed under the conditions shown below, as evidenced by theinability to produce sheets having greater than 95% draw and noblistering, without predrying the sheets prior to thermoforming.

Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 120 197 825100 H B 101 177 820 99 H C 95 174 781 95 L D 85 171 727 88 L E 83 166558 68 L

Example 18 Comparative Example

A miscible blend consisting of 70 wt % Teijin L-1250 polycarbonate,29.85 wt % PCTG 25976, and 0.15 wt % Weston 619 was produced using a1.25 inch single screw extruder. Sheets consisting of the blend werethen produced using a 3.5 inch single screw extruder. A sheet wasextruded continuously, gauged to a thickness of 118 mil and then varioussheets were sheared to size. The glass transition temperature wasmeasured on one sheet and was 123° C. Sheets were then conditioned at50% relative humidity and 60° C. for 4 weeks. The moisture level wasmeasured to be 0.205 wt %. Sheets were subsequently thermoformed into afemale mold having a draw ratio of 2.5:1 using a Brown thermoformingmachine. The thermoforming oven heaters were set to 70/60/60% outputusing top heat only. Sheets were left in the oven for various amounts oftime in order to determine the effect of sheet temperature on the partquality as shown in the table below. Part quality was determined bymeasuring the volume of the thermoformed part, calculating the draw, andvisually inspecting the thermoformed part. The draw was calculated asthe part volume divided by the maximum part volume achieved in this setof experiments (Examples A and B). The thermoformed part was visuallyinspected for any blisters and the degree of blistering rated as none(N), low (L), or high (H). The results below demonstrate that thesethermoplastic sheets with a glass transition temperature of 123° C.cannot be thermoformed under the conditions shown below, as evidenced bythe inability to produce sheets having greater than 95% draw and noblistering, without predrying the sheets prior to thermoforming.

Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 126 198 826100 H B 111 188 822 100 H C 97 177 787 95 L D 74 166 161 19 L E 58 154 00 NA F 48 149 0 0 NA NA = not applicable. A value of zero indicates thatthe sheet was not formed because it did not pull into the mold (likelybecause it was too cold).

Example 19 Comparative Example

Sheets consisting of Teijin L-1250 polycarbonate were produced using a3.5 inch single screw extruder. A sheet was extruded continuously,gauged to a thickness of 118 mil and then various sheets were sheared tosize. The glass transition temperature was measured on one sheet and was149° C. Sheets were then conditioned at 50% relative humidity and 60° C.for 4 weeks. The moisture level was measured to be 0.16 wt %. Sheetswere subsequently thermoformed into a female mold having a draw ratio of2.5:1 using a Brown thermoforming machine. The thermoforming ovenheaters were set to 70/60/60% output using top heat only. Sheets wereleft in the oven for various amounts of time in order to determine theeffect of sheet temperature on the part quality as shown in the tablebelow. Part quality was determined by measuring the volume of thethermoformed part, calculating the draw and visually inspecting thethermoformed part. The draw was calculated as the part volume divided bythe maximum part volume achieved in this set of experiments (Example A).The thermoformed part was visually inspected for any blisters and thedegree of blistering rated as none (N), low (L), or high (H). Theresults below demonstrate that these thermoplastic sheets with a glasstransition temperature of 149° C. cannot be thermoformed under theconditions shown below, as evidenced by the inability to produce sheetshaving greater than 95% draw and no blistering, without predrying thesheets prior to thermoforming.

Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 152 216 820100 H B 123 193 805 98 H C 113 191 179 22 H D 106 188 0 0 H E 95 182 0 0NA F 90 171 0 0 NA NA = not applicable. A value of zero indicates thatthe sheet was not formed because it did not pull into the mold (likelybecause it was too cold).

It can be clearly seen from a comparison of the data in the aboverelevant working examples that the polyesters of the present inventionoffer a definite advantage over the commercially available polyesterswith regard to glass transition temperature, density, slowcrystallization rate, melt viscosity, and toughness.

The invention has been described in detail with reference to theembodiments disclosed herein, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

1. A film or sheet comprising at least one polyester compositioncomprising at least one polyester which comprises: (a) a dicarboxylicacid component comprising: i) 80 to 100 mole % of terephthalic acidresidues; ii) 0 to 20 mole % of aromatic dicarboxylic acid residueshaving up to 20 carbon atoms; and iii) 0 to 10 mole % of aliphaticdicarboxylic acid residues having up to 16 carbon atoms; and (b) aglycol component comprising: i) 15 to 25 mole % of2,2,4,4-tetramethyl-1,3-cyclobutanediol residues; and ii) 75 to 85 mole% of 1,4-cyclohexanedimethanol residues, wherein the total mole % of thedicarboxylic acid component is 100 mole %, and the total mole % of theglycol component is 100 mole %; wherein the inherent viscosity of saidpolyester is 0.60 to 0.75 dL/g as determined in 60/40 (wt/wt)phenol/tetrachloroethane at a concentration of 0.5 g/100 ml at 25° C.;wherein the glass transition temperature of the polyester is from 100 to125° C.; wherein the polyester has a notched Izod impact strength of atleast 7.5 ft-lb/inch at 23° C. according to ASTM D256 with a 10 milnotch in a ⅛ inch thick bar; wherein the melt viscosity of the polyesteris less than 10,000 poise as measured at 1 radian/second on a rotarymelt rheometer at 290° C.; and wherein said polyester compositioncontains no polycarbonate.
 2. The film or sheet of claim 1, wherein theinherent viscosity of said polyester is from 0.65 to 0.75 dL/g.
 3. Thefilm or sheet of claim 1, wherein the inherent viscosity of saidpolyester is from 0.70 to 0.75 dL/g.
 4. The film or sheet of claim 1,wherein the inherent viscosity is from 0.60 to 0.72 dL/g.
 5. The film orsheet of claim 1, 2 or 3, wherein the glycol component of said polyestercomprises 20 to 25 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediolresidues and 75 to 80 mole % 1,4-cyclohexanedimethanol residues.
 6. Thefilm or sheet of claim 1, wherein the glycol component of said polyestercomprises 15 to 20 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediolresidues and 80 to 85 mole % 1,4-cyclohexanedimethanol residues.
 7. Thefilm or sheet of claim 1, wherein the dicarboxylic acid component ofsaid polyester comprises 90 to 100 mole % of terephthalic acid residues.8. The film or sheet of claim 1, wherein the polyester comprises from0.01 to 10 mole % of ethylene glycol residues.
 9. The film or sheet ofclaim 1, wherein the 2,2,4,4-tetramethyl -1,3-cyclobutanediol residuesare a mixture comprising from 70 to 30 mole % oftrans-2,2,4,4-tetramethyl-1,3-cyclobutanediol residues and from 30 to 70mole % of cis-2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.
 10. Thefilm or sheet of claim 1, wherein cis portion of the cis/trans ratio ofthe 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues is greater than 50mole %.
 11. The film or sheet of claim 1, wherein the polyester has adensity of between 1.1 to less than 1.2 g/ml at 23° C.
 12. The film orsheet of claim 1, wherein the polyester has a notched Izod impactstrength using a ¼ inch bar of at least 10 ft-lb/inch at 23° C.
 13. Thefilm or sheet of claim 1, further comprising at least one polymerselected from polyamides, polystyrene, styrene copolymers, styreneacrylonitrile copolymers, acrylonitrile butadiene styrene copolymers,poly(methyl methacrylate), acrylic polymers and copolymers,poly(etherimides), polyphenylene oxides, poly(phenyleneoxide)/polystyrene blends, polystyrene resins, polyphenylene sulfides,polyphenylene sulfide/sulfones, polysulfones; polysulfone ethers, orpoly(ether-ketones) or a mixture thereof.
 14. The film or sheet of claim1, wherein the glass transition temperature of the polyester is from 100to 120° C.
 15. The film or sheet of claim 1, wherein the glasstransition temperature of the polyester is from 105 to 120° C.
 16. Thefilm or sheet of claim 1, wherein the glass transition temperature ofthe polyester is from 105 to 115° C.
 17. The film or sheet of claim 1,wherein said polyester comprises residues of at least one branchingagent in an amount of 0.01 to 10 mole % based on the total molepercentages of acid residues or diol residues.
 18. The film or sheet ofclaim 1, wherein the melt viscosity of said polyester is less than 6,000poise as measured at 1 radian/second on a rotary melt rheometer at 280°C.
 19. The film or sheet of claim 1, further comprising at least oneadditive selected from the group consisting of colorants, dyes, moldrelease agents, flame retardants, plasticizers, nucleating agents, UVstabilizers, glass fiber, carbon fiber, fillers, impact modifiers, ormixtures thereof.
 20. The film or sheet of claim 1, wherein thepolyester comprises residues of at least one catalyst comprising a tincompound or a reaction product thereof.
 21. An article of manufacturecomprising the film or sheet of claim
 1. 22. A film or sheet comprisingat least one polyester composition comprising at least one polyesterwhich comprises: (a) a dicarboxylic acid component comprising: i) 80 to100 mole % of terephthalic acid residues; ii) 0 to 20 mole % of aromaticdicarboxylic acid residues having up to 20 carbon atoms; and iii) 0 to10 mole % of aliphatic dicarboxylic acid residues having up to 16 carbonatoms; and (b) a glycol component comprising: i) 20 to 25 mole % of2,2,4,4-tetramethyl-1,3-cyclobutanediol residues; and ii) 75 to 80 mole% of 1,4-cyclohexanedimethanol residues, wherein the total mole % of thedicarboxylic acid component is 100 mole %, and the total mole % of theglycol component is 100 mole %; wherein the inherent viscosity of saidpolyester is from 0.68 to 0.75 dL/g as determined in 60/40 (wt/wt)phenol/tetrachloroethane at a concentration of 0.5 g/100 ml at 25° C.;and wherein the glass transition temperature of the polyester is from100 to 125° C.; wherein the polyester has a notched Izod impact strengthof at least 7.5 ft-lb/inch at 23° C. according to ASTM D256 with a 10mil notch in a ⅛ inch thick bar; wherein the melt viscosity of thepolyester is less than 10,000 poise as measured at 1 radian/second on arotary melt rheometer at 290° C.; and wherein said polyester compositioncontains no polycarbonate.
 23. A film or sheet comprising at least onepolyester composition comprising at least one polyester which comprises:(a) a dicarboxylic acid component comprising: i) 80 to 100 mole % ofterephthalic acid residues; ii) 0 to 20 mole % of aromatic dicarboxylicacid residues having up to 20 carbon atoms; and iii) 0 to 10 mole % ofaliphatic dicarboxylic acid residues having up to 16 carbon atoms; (b) aglycol component comprising: i) 15 to 25 mole % of 2, 2, 4,4-tetramethyl-1,3-cyclobutanediol residues; and ii) 75 to 85 mole % of1, 4-cyclohexanedimethanol residues; and (c) residues from at least onebranching agent in the amount of 0.01 to 10 mole % based on the totalmole percentage of the diacid residues or diol residues; wherein thetotal mole % of the dicarboxylic acid component is 100 mole %, and thetotal mole % of the glycol component is 100 mole %; and wherein theinherent viscosity of the polyester is 0.60 to 0.75 dig as determined in60/40 (wt/wt) phenol/tetrachloroethane at a concentration of 0.5 g/100ml at 25° C.; wherein the glass transition temperature of the polyesteris from 100 to 125° C.; wherein the polyester has a notched Izod impactstrength of at least 7.5 ft-lb/inch at 23° C. according to ASTM D256with a 10 mil notch in a ⅛ inch thick bar; wherein the melt viscosity ofthe polyester is less than 10,000 poise as measured at 1 radian/secondon a rotary melt rheometer at 290° C.; and wherein said polyestercomposition contains no polycarbonate.
 24. A film or sheet comprising atleast one polyester composition of claim 23, wherein the polyester hasan inherent viscosity of 0.60 to 0.72 dL/g.
 25. A film or sheetcomprising at least one polyester composition comprising: (I) at leastone polyester which comprises: (a) a dicarboxylic acid componentcomprising: i) 80 to 100 mole % of terephthalic acid residues; ii) 0 to20 mole % of aromatic dicarboxylic acid residues having up to 20 carbonatoms; and iii) 0 to 10 mole % of aliphatic dicarboxylic acid residueshaving up to 16 carbon atoms; and (b) a glycol component comprising: i)15 to 25 mole % of 2, 2, 4, 4-tetramethyl-1,3-cyclobutanediol residues;and ii) 75 to 85 mole % of 1, 4-cyclohexanedimethanol residues; and (II)at least one thermal stabilizer or the reaction product thereof chosenfrom at least one of phosphoric acid, phosphorous acid, phosphonic acid,phosphinic acid, phosphonous acid, or an ester or salt thereof; whereinthe total mole % of the dicarboxylic acid component is 100 mole %, andthe total mole % of the glycol component is 100 mole %; wherein theinherent viscosity of said polyester is 0.60 to 0.75 dL/g as determinedin 60/40 (wt/wt) phenol/tetrachloroethane at a concentration of 0.5g/100 ml at 25° C.; wherein the glass transition temperature of thepolyester is from 100 to 125° C.; wherein the polyester has a notchedIzod impact strength of at least 7.5 ft-lb/inch at 23° C. according toASTM D256 with a 10 mil notch in a ⅛ inch thick bar; and wherein themelt viscosity of the polyester is less than 10,000 poise as measured at1 radian/second on a rotary melt rheometer at 290° C.; and wherein saidpolyester composition contains no polycarbonate.
 26. A film or sheetcomprising at least one polyester composition of claim 25, wherein thepolyester has a Tg of 100 to 120° C.
 27. The polyester composition ofclaim 25, wherein the glass transition temperature of the polyester isfrom 105 to 115° C.
 28. The polyester composition of claim 25, whereinthe polyester composition comprises residues from at least one branchingagent in the amount of 0.01 to 5 mole % based on the total molepercentage of the diacid residues or diol residues.
 29. The polyestercomposition of claim 25, wherein the polyester composition comprises atleast one additive selected from the group consisting of colorants,dyes, mold release agents, flame retardants, plasticizers, nucleatingagents, UV stabilizers, glass fiber, carbon filaments, fillers, impactmodifiers, or mixtures thereof.
 30. The polyester composition of claim25, wherein the polyester comprises from 0.01 to 10 mole % of ethyleneglycol residues.
 31. The composition of claim 1, having a b* value offrom −10 to less than 10 and a L* value of from 50 to 90 according tothe L*, a* and b* color system of the CIE (International Commission onIllumination).
 32. The film or sheet of claim 22, 23 or 25, wherein saidpolyester has a notched Izod impact strength of at least 10 ft-lbs/in at23° C. according to ASTM D256 with a 10-mil notch in a ¼-inch thick bar.33. The film or sheet of claim 1, 22, 23 or 25, wherein said polyesterhas a notched Izod impact strength of at least 18 ft lbs/in at 23° C.according to ASTM D256 with a 10-mil notch in a ⅛-inch thick bar. 34.The film or sheet of claim 22, 23 or 25, wherein the melt viscosity ofsaid polyester is less than 6,000 poise as measured at 1 radian/secondon a rotary melt rheometer at 290° C.